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US5616684A - Cyclic peptides and use thereof - Google Patents

Cyclic peptides and use thereof Download PDF

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Publication number
US5616684A
US5616684A US08/231,449 US23144994A US5616684A US 5616684 A US5616684 A US 5616684A US 23144994 A US23144994 A US 23144994A US 5616684 A US5616684 A US 5616684A
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Mitsuhiro Wakimasu
Takashi Kikuchi
Akira Kawada
Hideo Shirafuji
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Takeda Pharmaceutical Co Ltd
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Takeda Chemical Industries Ltd
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
    • C07K14/575—Hormones
    • C07K14/57536—Endothelin, vasoactive intestinal contractor [VIC]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P11/00—Drugs for disorders of the respiratory system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P13/00—Drugs for disorders of the urinary system
    • A61P13/02—Drugs for disorders of the urinary system of urine or of the urinary tract, e.g. urine acidifiers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P15/00—Drugs for genital or sexual disorders; Contraceptives
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A61P3/06—Antihyperlipidemics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P9/00—Drugs for disorders of the cardiovascular system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P9/00—Drugs for disorders of the cardiovascular system
    • A61P9/12—Antihypertensives
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K7/00—Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
    • C07K7/64—Cyclic peptides containing only normal peptide links
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00—Medicinal preparations containing peptides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/55—Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups

Definitions

  • the present invention relates to novel cyclic peptides having antagonistic activity on endothelin receptors and antagonistic activity on NK2 receptors. These cyclic peptides are useful as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases, renal diseases and asthma, anti-inflammatory drugs, antarthritics and the like.
  • the present invention further relates to the use thereof.
  • Endothelin is a vasoconstrictive peptide composed of 21 amino acid residues. Endothelin was isolated from the culture supernatant of the endothelial cells of porcine aortas. Its structure was determined by M. Yanagisawa et al. in 1988 [M. Yanagisawa et al., Nature 332, 411-412 (1988)]. More recently, the research on genes coding for endothelin revealed the presence of peptides similar to endothelin in structure. These peptides are named endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3), respectively. Their structures are as follows:
  • peptides of the endothelin family exist in vivo and have vasopressor activity. For this reason, these peptides are anticipated to be intrinsic factors responsible for the control of circulatory systems, and deduced to be related to hypertension, cardiac or cerebral circulatory diseases such as cardiac infarction and renal diseases such as acute renal insufficiency. In addition, these peptides also have bronchial smooth muscle constrictor activity, and therefore deduced to be related to asthma.
  • the present inventors prepared novel cyclic peptides having the antagonistic activity on the endothelin receptors, and further discovered that a certain group of the peptides thus obtained had the antagonistic activity on the NK2 receptors, completing the present invention by further studies.
  • the present invention provides
  • a pharmaceutical composition comprising the peptide represented by formula [I] or a pharmaceutically acceptable salt thereof as an active ingredient, in for example, an endothelin receptor antagonist effective amount or an NK2 receptor antagonist effective amount.
  • the hexapeptide represented by formula [I] has 6 amide bonds including a bond between A and D, thereby showing that the molecule forms a ring as a whole.
  • this hexapeptide is sometimes referred to as cyclo[-A-X-Y-B-C-D-].
  • an amino acid which forms the ⁇ -amino acid residue represented by X or Y may be any amino acid as long as it is an ⁇ -amino acid.
  • Examples thereof include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, 2-aminomalonic acid, 2-aminoadipic acid, glycine, histidine, isoleucine, leucine, lysine, ornithine, 2,4-diaminobutyric acid, methionine, phenylalanine, proline, 4-hydroxyproline, thioproline, azetidine-2-carboxylic acid, pipecolic acid (piperidine-2-carboxylic acid), indoline-2-carboxylic acid, tetrahydroisoquinoline-3-carboxylic acid, serine, threonine, tryptophan, 5-methyltryptophan, tyrosine, valine, all
  • the substituted hydroxyl groups include esters such as C 1-6 fatty acid esters (for example, formates, acetates and propionates), C 4-9 alicyclic carboxylic acid esters (for example, cyclopentanecarboxylates and cyclohexanecarboxylates), C 7-15 arylcarboxylic acid esters (for example, benzoates and 4-methylbenzoates), C 8-16 aralkylcarboxylic acid esters (for example, phenylacetates, 2-phenylpropionates, 3-phenylpropionates and diphenylacetates) and aromatic heterocycle-alkylcarboxylic acid esters (for example, indole-2-ylacetates and indole-3-ylacetates); and ethers such as C 1-6 alkyl ethers (for example, methyl ethers, ethyl ethers, n-propyl ethers and t-butyl ethers), C 3
  • Examples of the ⁇ -amino acids whose hydroxyl groups are substituted include O-acetylserine, O-acetylthreonine, 4-acetoxyproline, O-benzoylserine, O-benzoylthreonine, 4-benzoyloxyproline, O-phenylacetylserine, O-phenylacetylthreonine, 4-phenylacetoxyproline, O-ethylserine, O-ethylthreonine, 4-ethoxyproline, O-cyclohexylserine, O-cyclohexylthreonine, 4-cyclohexyloxyproline, O-phenylserine, O-phenylthreonine, 4-phenoxyproline, O-benzylserine, O-benzylthreonine, 4-benzyloxyproline, O-diphenylmethylserine, O-diphenylmethylthreonine and 4-diphen
  • the substituted thiol groups include thiol esters such as C 1-6 fatty acid thiol esters (for example, formic acid thiol esters, acetic acid thiol esters and propionic acid thiol esters), C 4-9 alicyclic carboxylic acid thiol esters (for example, cyclopentanecarboxylic acid thiol esters and cyclohexanecarboxylic acid thiol esters), C 7-15 arylcarboxylic acid thiol esters (for example, benzoic acid thiol esters and 4-methylbenzoic acid thiol esters) and C 8-16 aralkylcarboxylic acid thiol esters (for example, phenylacetic acid thiol ester, 2-phenylpropionic acid thiol esters, 3-phenylpropionic acid thiol esters and diphenylacetic acid thiol esters); and thioether forms
  • Examples of the ⁇ -amino acids whose thiol groups are substituted include S-acetyl-cysteine, S-benzoylcysteine, S-phenylacetylcysteine, S-ethylcysteine, S-cyclohexylcysteine, S-phenylcysteine and S-benzylcysteine.
  • the substituted amino groups (or imino groups) include substituted amino or imino groups such as C 1-6 alkylamino (or imino) [for example, N-methylamino (or imino), N-ethylamino (or imino) and N-t-butylamino (or imino)], C 3-8 cycloalkyl-amino (or imino) [for example, N-cyclopentylamino (or imino) and N-cyclohexylamino (or imino)], C 6-12 arylamino (or imino) [for example, N-phenylamino (or imino) and N- ⁇ 4-methylphenyl ⁇ amino (or imino)], C 7-15 aralkylamino (or imino) [for example, N-benzylamino (or imino), N-phenethyl-amino (or imino), N- ⁇ 2-chlorobenzyl ⁇ a
  • Examples of the ⁇ -amino acids whose amino (or imino) groups are substituted include N-methylglycine (sarcosine), N-ethylglycine, N-methylleucine, N-ethylleucine, N-methylphenylalanine, N-ethylphenylalanine, N( ⁇ )-methyltryptophan, N( ⁇ )-ethyltryptophan, N-cyclopentylglycine, N-cyclohexylglycine, N-phenylglycine, N-phenylleucine, N-benzylglycine, N-benzylleucine, N( ⁇ )-benzylhistidine, N( ⁇ )-benzylhistidine, N( ⁇ )-phenacylhistidine, N( ⁇ )-benzyloxymethylhistidine, N g -benzenesulfonylarginine, N g -p-toluenesulfony
  • the substituted carboxyl groups include amido groups such as carboxylic acid amido (--CONH 2 ), N--C 1-6 alkylamido (for example, N-methylamido, N-ethylamido, N- ⁇ n-propyl ⁇ amido and N-t-butylamido), N--C 3-8 cycloalkylamido (for example, N-cyclopentylamido and N-cyclohexylamido), N--C 6-12 arylamido (for example, N-phenylamido and N- ⁇ 4-methylphenyl ⁇ amido), N--C 7-15 aralkylamido (for example, N-benzylamido, N-phenethylamido, N- ⁇ 1,2-diphenylethyl ⁇ amido), N- ⁇ aromatic heterocycle-C 1-6 alkyl ⁇ amido (for example, N-[2- ⁇ indole-2-yl ⁇ ethyl]amido
  • amido forms also include amido groups with ⁇ -amino acids and amido groups with oligopeptides (for example, dipeptides, tripeptides and tetrapeptides).
  • the ⁇ -amino acids whose carboxyl groups are substituted include, for example, N 4 -methylasparagine, N 4 -phenylasparagine, N 4 -benzylasparagine, N 4 -phenethylasparagine, N 4 -(2- ⁇ indole-3-yl ⁇ ethyl)asparagine, N 5 -methylglutamine, N 5 -phenylglutamine, N 5 -benzylglutamine, N 5 -phenethylglutamine, N 5 -(2- ⁇ indole-3-yl ⁇ ethyl)glutamine, aspartic acid ⁇ -methyl ester, aspartic acid ⁇ -cyclopropyl ester, aspartic acid ⁇
  • the ⁇ -amino acid which forms the amino acid residue represented by X or Y in formula [I] may be any of the L-, D- and DL-forms.
  • the L-form is, however, more preferred in each case.
  • An amino acid which forms the D-acidic- ⁇ -amino acid residue represented by A in formula [I] is, for example, an amino acid with an acidic group such as carboxyl, sulfonyl or tetrazolyl as a side chain.
  • amino acids include D-glutamic acid, D-aspartic acid, D-cysteic acid, D-homocysteic acid, D- ⁇ -(5-tetrazolyl)alanine and D-2-amino-4-(5-tetrazolyl)butyric acid.
  • D-glutamic acid, D-aspartic acid and D-cysteic acid are preferred.
  • An amino acid which forms the neutral- ⁇ -amino acid residue represented by B in formula [I] is an ⁇ -amino acid.
  • ⁇ -amino acids include alanine, valine, norvaline, leucine, isoleucine, alloisoleucine, norleucine, tertiary leucine, ⁇ -methylleucine, phenylglycine, phenylalanine, 1-naphthylalanine, 2-naphthylalanine, proline, 4-hydroxyproline, azetidine-2-carboxylic acid, pipecolic acid (piperidine-2-carboxylic acid), 2-thienylalanine, 2-thienylglycine, 3-thienylglycine, 1-aminocyclopropane-1-carboxylic acid, 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, 1-aminocyclohexan
  • D-form When the above-mentioned neutral- ⁇ -amino acid exists in the L- and D-forms, the D-form is preferred.
  • D-Leucine, D-alloisoleucine, D-tertiary leucine, D- ⁇ -methylleucine, D-phenylglycine, D-2-thienylalanine, D-2-thienylglycine, D-3-thienylglycine and D-2-cyclopentylglycine are preferred among others.
  • ⁇ -Imino groups of these neutral- ⁇ -amino acids may be substituted by C 1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl).
  • ⁇ -amino acids examples include N-methylleucine, N-methylalloisoleucine, N-methyl tertiary leucine, N-methyl ⁇ -methylleucine and N-methylphenyl-glycine. Also for these ⁇ -amino acids, the D-form is preferred.
  • L- ⁇ -amino acid As an amino acid which forms the L- ⁇ -amino acid residue represented by C in formula [I], used is an L- ⁇ -amino acid usually known in the art.
  • L- ⁇ -amino acids include glycine, L-alanine, L-valine, L-norvaline, L-leucine, L-isoleucine, L-tertiary leucine, L-norleucine, L-methionine, L-2-aminobutyric acid, L-serine, L-threonine, L-phenylalanine, L-aspartic acid, L-glutamic acid, L-asparagine, L-glutamine, L-lysine, L-tryptophan, L-arginine, L-tyrosine and L-proline.
  • L-leucine, L-norleucine and L-tryptophan are preferred.
  • ⁇ -Imino groups of these L- ⁇ -amino acids may be substituted by C 1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl).
  • Examples of such L- ⁇ -amino acids include L-N-methylleucine, L-N-methylnorleucine and L-N( ⁇ )-methyltryptophan.
  • an amino acid which forms the D- ⁇ -amino acid residue with the aromatic ring group represented by D in formula [I] used is a D- ⁇ -amino acid having an aromatic ring group as a side chain.
  • Preferred examples thereof include D-tryptophan, D-5-methyltryptophan, D-phenylalanine, D-tyrosine, D-1-naphthylalanine, D-2-naphthylalanine, D-3-benzothienylalanine, D-4-biphenylalanine and D-pentamethylphenylalanine.
  • D-Tryptophan and D-5-methyltryptophan are preferred, and particularly, D-tryptophan is more preferred.
  • the ⁇ -imino groups of the D- ⁇ -amino acids having the aromatic rings may be substituted by C 1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl).
  • the imino group of the indole ring of D-tryptophan may be substituted by a hydrocarbon group such as a C 1-6 alkyl group (for example, methyl, ethyl, n-propyl or t-butyl), a C 3-8 cycloalkyl group (for example, cyclopentyl or cyclohexyl), a C 6-12 aryl group (for example, phenyl, or 4-methylphenyl) or C 7-15 aralkyl (for example, benzyl or phenethyl), or an acyl group such as a C 1-6 aliphatic acyl group (for example, formyl, acetyl or propionyl), a
  • Examples of such ⁇ -amino acids include D-N( ⁇ )-methyltryptophan, D-N-methylphenylalanine, D-N-methyltyrosine, D-N in -methyltryptophan, D-N in -ethyltryptophan, D-N in -formyltryptophan and D-N in -acetyltryptophan.
  • D-N in -methyltryptophan, D-N in -formyltryptophan and D-N in -acetyltryptophan are preferred among others.
  • X has L-configuration.
  • Y has L-configuration.
  • A is selected from the group consisting of D-glutamic acid, D-aspartic acid, D-cysteic acid and D- ⁇ -(5-tetrazolyl)alanine residue.
  • B is selected from the group consisting of 1-aminocyclopropane-1-carboxylic acid, 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, 1-aminocyclohexane-1-carboxylic acid and 1-aminocycloheptane-1-carboxylic acid residue.
  • B is selected from the group consisting of D-leucine, D-alloisoleucine, D-tertiaryleucine, D-gammamethylleucine, D-phenylglycine, D-2-thienylglycine, D-3-thienylglycine, D-cyclopentylglycine, D-phenylalanine, D-2-thienylalanine, D-valine, D-2-furylhglycine and D-3-furylglycine residue.
  • C is selected from the group consisting of L-leucine, L-isoleucine, L-valine, L-norleucine and L- ⁇ -amino acid residue having aromatic moiety.
  • C is selected from the group consisting of L-leucine, L-phenylalanine and L-tryptophan.
  • D is D-tryptophan, or a derivative thereof, D-1-naphthylalanine, D-2-naphthylalanine, D-benzothienylalanine, D-4-bisphenylalanine and D-pentamethylphenylalanine residue.
  • the derivative of tryptophan is selected from the group consisiting of D-N in -methyltryptophan, D-N in -formyltryptophan and D-N in -acetyltryptophan residue.
  • each parameter include such as those in which A is D-aspartic acid residue;
  • X is tryptophan, L-( ⁇ -4-phenylpiperazine amide)aspartic acid, L-(N.sup. ⁇ -phenylacetyl)ornithine, L-(N 4 -[indol-3-yl]ethyl)ornithine, L-(4-benzyloxy)proline, L-(N 5 -benzyl)glutamine or L-(N.sup. ⁇ -[indol-3-yl]acetyl)asparagine residue;
  • Y is L-leucine, L-aspartic acid, L-O-benzylserine, tryptophan, serine or proline residue;
  • B is D-leucine, D-2-thienylglycine or D-3-thienylglycine residue;
  • cyclic peptides represented by formula [I] of the present invention have the antagonistic activity on endothelin receptors.
  • the peptides having amino acid residues such as aspartic acid and tryptophan as X and amino acid residues such as leucine, tryptophan and O-benzylserine as Y further also have the antagonistic activity on NK2 receptors.
  • the salts of the cyclic peptides [I] include metal salts (for example, sodium salts, potassium salts, calcium salts and magnesium salts), salts of bases or basic compounds (for example, ammonium salts and arginine salts), addition salts of inorganic acids (for example, hydrochlorides, sulfates and phosphates), and salts of organic acids (for example, acetates, propionates, citrates, tartarates, malates and oxalates).
  • metal salts for example, sodium salts, potassium salts, calcium salts and magnesium salts
  • salts of bases or basic compounds for example, ammonium salts and arginine salts
  • addition salts of inorganic acids for example, hydrochlorides, sulfates and phosphates
  • salts of organic acids for example, acetates, propionates, citrates, tartarates, malates and oxalates.
  • the cyclic peptides [I] of the present invention can be produced by methods for peptide synthesis known in the art, which may be either solid phase synthesis methods or liquid phase synthesis methods. In some cases, the liquid phase synthesis methods are preferred. Examples of such methods for peptide synthesis include methods described in M. Bodansky and M. A. Ondetti, Peptide Synthesis., Interscience, New York (1966); F. M. Finn and K. Hofmann, The Proteins, Vol. 2, edited by H. Nenrath and R. L. Hill, Academic Press, New York, (1976); N.
  • the cyclic peptide [I] of the present invention can be produced by condensing a first starting material having a reactive carboxyl group corresponding to one of two kinds of fragments which are separated at any position of its peptide bond with a second starting material having a reactive amino group corresponding to the other fragment, subsequently eliminating protective groups of the C-terminal ⁇ -carboxyl group and the N-terminal ⁇ -amino group of the resulting compound concurrently or stepwise, thereafter conducting intramolecular condensation of both by methods known in the art to obtain a cyclic compound, and then, eliminating protective groups by methods known in the art, if the resulting condensed product has any protective groups.
  • the above starting materials are usually amino acid and/or peptide fragments which, taken together, form the cyclic hexapeptide of the desired formula [I] or a salt thereof. They are usually linear or branched.
  • the reactive carboxyl group means carboxyl group itself or an activated carboxyl group.
  • the reactive amino group means amino group itself or an activated amino group.
  • One of the two functional groups taking part in the condensation reaction is usually activated.
  • the carboxyl group and the amino group which do not take part in the condensation reaction are usually protected before the condensation reaction.
  • Protection of functional groups which should not affect the reaction of the starting materials, the protective groups and elimination of the protective groups, and activation of functional groups related to the reaction can also be suitably selected from groups or methods known in the art.
  • Examples of the protective groups for the amino groups of the starting materials include benzyloxycarbonyl, t-butyloxy-carbonyl, t-amyloxycarbonyl, isobornyloxycarbonyl, 4-methoxybenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, adamantyloxycarbonyl, trifluoroacetyl, phthalyl, formyl, 2-nitrophenylsulfenyl, diphenylphosphinothioyl and 9-fluorenylmethyloxycarbonyl.
  • the protective groups for the carboxyl groups include, for example, alkyl esters (such as esters of methyl, ethyl, propyl, butyl, t-butyl, cyclo-pentyl, cyclohexyl, cycloheptyl, cyclooctyl and 2-adamantyl), benzyl esters, 4-nitrobenzyl esters, 4-methoxybenzyl esters, 4-chlorobenzyl esters, benzhydryl esters, phenacyl esters, benzyloxycarbonylhydrazide, t-butyloxycarbonylhydrazide and tritylhydrazide.
  • alkyl esters such as esters of methyl, ethyl, propyl, butyl, t-butyl, cyclo-pentyl, cyclohexyl, cycloheptyl, cyclooctyl and 2-adamantyl
  • the hydroxyl group of serine can be protected, for example, by esterification or etherification.
  • groups suitable for this esterification include lower aliphatic acyl groups such as acetyl, arylacyl groups such as benzoyl, and carbonic acid-derived groups such as benzyloxycarbonyl and ethyloxycarbonyl.
  • groups suitable for the etherification include benzyl, tetrahydropyranyl and t-butyl.
  • the hydroxyl group of serine is not always required to be protected.
  • Examples of the protective groups for the phenolic hydroxyl group of tyrosine include benzyl, 2,6-dichlorobenzyl, 2-nitrobenzyl, 2-bromobenzyloxycarbonyl and t-butyl.
  • the phenolic hydroxyl group of tyrosine is not always required to be protected.
  • Methionine may be protected in the form of sulfoxides.
  • the protective groups for the imidazole ring of histidine include p-toluenesulfonyl, 4-methoxy-2,3,6-trimethylbenzenesulfonyl, 2,4-dinitrophenyl, benzyloxymethyl, t-butoxymethyl, t-butoxycarbonyl, trityl and 9-fluorenylmethyloxycarbonyl.
  • the imidazole ring is not always required to be protected.
  • the protective groups for the indole ring of tryptophan include formyl, 2,4,6-trimethylbenzensulfonyl, 2,4,6-trimethoxybenzenesulfonyl, 4-methoxy-2,3,6-trimethylbenzenesulfonyl, 2,2,2-trichloroethyloxycarbonyl and diphenylphosphinothioyl.
  • the indole ring is not always required to be protected.
  • Examples of the activated carboxyl groups of the starting materials include the corresponding acid anhydrides, azides and active esters (esters of alcohols such as pentachloro-phenol, 2,4,5-trichlorophenol, 2,4-dinitrophenol, cyano-methyl alcohol, p-nitrophenol, N-hydroxy-5-norbornene-2,3-dicarboxyimide, N-hydroxysuccinimide, N-hydroxyphthalimide and N-hydroxybenzotriazole.
  • Examples of the activated amino acid groups of the raw materials include the corresponding phosphoric acid amides.
  • Condensation reaction can be conducted in the presence of a solvent(s).
  • the solvent(s) can be appropriately selected from the solvents commonly used in peptide condensation reactions.
  • the solvents include anhydrous or hydrous dimethylformamide, dimethyl sulfoxide, pyridine, chloroform, dioxane, dichloromethane, tetrahydrofuran, acetonitrile, ethyl acetate, N-methylpyrrolidone and appropriate mixtures thereof.
  • the reaction temperature is appropriately selected from the temperature range commonly used in peptide bond-forming reactions, usually from the range of about -20° to about 30° C.
  • Intramolecular cyclization reaction can be conducted at any position of the peptide by methods known in the art.
  • the protective group of the C-terminal ⁇ -carboxyl group of the protected peptide is first eliminated by methods known in the art, and then, the carboxyl group is activated by methods known in the art, followed by elimination of the protective group of the N-terminal ⁇ -amino group by methods known in the art and intramolecular cyclization.
  • the protective groups of the C-terminal ⁇ -carboxyl group and the N-terminal ⁇ -amino group of the protected peptide may be concurrently eliminated, followed by intramolecular cyclization according to known condensation reaction.
  • intramolecular cyclization reaction is preferably conducted in a highly diluted state.
  • Examples of methods for eliminating the protective groups include catalytic reduction in the presence of a catalyst such as palladium black or Pd-carbon in a stream of hydrogen, acid treatment with anhydrous hydrogen fluoride, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid or mixtures thereof, and reduction with sodium in liquid ammonia.
  • a catalyst such as palladium black or Pd-carbon in a stream of hydrogen
  • acid treatment with anhydrous hydrogen fluoride, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid or mixtures thereof and reduction with sodium in liquid ammonia.
  • the elimination reaction by the above-mentioned acid treatment is generally conducted at a temperature between -20° and 40° C.
  • a cation trapping agent such as anisole, phenol, thioanisole, m-cresol, p-cresol, dimethylsulfide, 1,4-butanedithiol or 1,2-ethanedithiol.
  • a cation trapping agent such as anisole, phenol, thioanisole, m-cresol, p-cresol, dimethylsulfide, 1,4-butanedithiol or 1,2-ethanedithiol.
  • the formyl group used as the protective group for the indole ring of tryptophan may be eliminated by either (i) alkali treatment using dilute sodium hydroxide, dilute ammonia or the like, or (ii) the above-mentioned elimination by the acid treatment in the presence of 1,2-ethanedithiol, 1,4-butanedithiol or the like.
  • the cyclic peptide [I] thus obtained is collected by conventional separation and purification methods of peptides such as extraction, distribution, reprecipitation, recrystallization, column chromatography and high performance liquid chromatography.
  • the cyclic peptides [I] of the present invention can be obtained by methods known in the art as the metal salts, the salts of bases or basic compounds, the inorganic acid addition salts, the organic acid salts and the like, and particularly as pharmaceutically acceptable acid addition salts such as the salts of inorganic acids (for example, hydrochloric acid, sulfuric acid and phosphoric acid) or organic acids (for example, acetic acid, propionic acid, citric acid, tartaric acid, malic acid, oxalic acid and methanesulfonic acid).
  • inorganic acids for example, hydrochloric acid, sulfuric acid and phosphoric acid
  • organic acids for example, acetic acid, propionic acid, citric acid, tartaric acid, malic acid, oxalic acid and methanesulfonic acid.
  • the cyclic peptides of the present invention have the following pharmacological activity. Namely, the novel cyclic peptides [I] of the present invention or the pharmaceutically acceptable salts thereof have the antagonistic activity on endothelin receptors as shown in the experimental examples described below. Further, the certain group of cyclic peptides [I] or pharmaceutically acceptable salt thereof also have the antagonistic activity on NK2 receptors.
  • the cyclic peptides [I] or pharmaceutically acceptable salt thereof can be used as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases, renal diseases, asthma and the like, because they have the antagonistic activity on endothelin receptors. Further, the cyclic peptides [I] or pharmaceutically acceptable salt thereof having the antagonistic activity on NK2 receptors in addition can also be used as anti-inflammatory drugs and antarthritics.
  • Preferred novel cyclic peptides [I] of the present invention strongly bind not only to ET A , but also to ET B to act as the antagonists on endothelin receptors, as shown in the experimental examples described below. Further, the certain group of the novel cyclic peptides [I] of the present invention have the antagonistic activity on NK2 receptors, one of tachykinin peptide receptors, in addition.
  • substance P, neurokinin A and neurokinin B are known [Y. Yokoto et al., J. Biol. Chem., 264, 17649 (1989); A. D. Hershey et al., Science, 247, 958 (1990); Y.
  • NK1, NK2 and NK3 are known respectively, as receptors corresponding to ligands thereof.
  • Antagonists on NK receptors are described in Japanese Patent Unexamined Publication Nos. 2197/1991, 17098/1991 and 141295/1991.
  • the compounds disclosed therein are different from the cyclic hexapeptides [I] of the present invention in structure.
  • novel cyclic peptides [I] of the present invention have the remarkable effect of suppressing the vasopressor activity of endothelin as the antagonists on endothelin receptors, and some of them also have the strong activity as the antagonists on NK2 receptors.
  • the novel cyclic peptides of the present invention or the salts thereof can be used as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases (for example, cardiac infarction), renal diseases for example, acute renal insufficiency), asthma and the like.
  • the cyclic peptides having the antagonistic activity on NK2 receptors in addition can also be used as the anti-inflammatory drugs and the antarthritics.
  • the cyclic peptides of the present invention when used as the above-mentioned prophylactic and therapeutic drugs, can be safely administered orally or parenterally in the form of powders, granules, tablets, capsules, injections, suppositories, ointments or sustained release preparations, alone or in combination with pharmaceutically acceptable carriers, excipients or diluents.
  • the peptides of the present invention are typically administered parenterally, for example, by intravenous or subcutaneous injection, intraventricular or intraspinal administration, nasotracheal administration or intrarectal administration. In some cases, however, they are administered orally.
  • the cyclic peptides of the present invention are generally stable substances, and therefore, can be stored as physiological saline solutions. It is also possible to lyophilize the peptides, store them in ampules with mannitol or sorbitol, and dissolve them in a suitable carrier at the time of use.
  • the cyclic peptides of the present invention can be given in their free forms, or in the form of base salts or acid addition salts thereof. All of the free cyclic peptides, the base salts and the acid addition salts thereof are generally given in a proper dose within the range of 1 ⁇ g to 100 mg of free peptide per kg of weight.
  • the dosage varies depending on the type of disease to be treated, the symptom of the disease, the object to which the drugs are given and the route of administration, when given by injection to adult patients of hypertension, for example, it is advantageous that the active ingredients (the peptides [I] or pharmaceutically acceptable salt thereof) are normally given in one dose of about 1 ⁇ g to 100 mg/kg of weight, more preferably about 100 ⁇ g to 20 mg/kg of weight, most preferably 1 mg to 20 mg/kg of weight, about once to 3 times a day.
  • the peptides [I] are usually given intravenously. Drip infusion is also effective. In this case, the total dosage is the same as with injection.
  • cyclic peptides of the present invention or the pharmaceutically acceptable salts thereof are used as the prophylactic or therapeutic drugs, they must be carefully purified so as to contain no bacteria and no pyrogens.
  • SILICAGEL 60F-254 (Merck) was used as the plates of thin layer chromatography, and chloroform-methanol (19:1) and chloroform-methanol-acetic acid (9:1:0.5) were used as the developing solvents for Rf 1 and Rf 2 , respectively.
  • H-Leu-OBzl.pTos (21.6 g) was dissolved in DMF (100 ml), and the solution was cooled with ice.
  • TEA (7.7 ml) and Boc-D-Leu-ONB [prepared from Boc-D-Leu-OH.H 2 O (12.5 g), HONB (9.86 g) and DCC (11.4 g) were added thereto, followed by stirring overnight.
  • the resulting DCU was separated by filtration, and the filtrate was concentrated to obtain a residue.
  • the residue was dissolved in AcOEt, and the resulting solution was washed with 4% aqueous NaHCO 3 and 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Leu-Leu-OBzl (6.0 g) was dissolved in methanol (20 ml) and catalytically reduced in a stream of hydrogen using 10% Pd-carbon as a catalyst. After the catalyst was separated by filtration, the solution was concentrated to obtain a residue. The residue and Cs 2 CO 3 (2.1 g) were dissolved in 90% aqueous methanol, and the solution was concentrated. The resulting residue was dissolved in DMF (60 ml), and phenacyl bromide (2.8 g) was added thereto, followed by stirring overnight. The resulting TEA hydrochloride was separated by filtration, and the filtrate was concentrated to obtain a residue.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.77 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.60 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml), and cooled with ice. Then, TEA (0.48 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.47 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8-N HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (1.85 g) prepared in EXAMPLE 1 (2) to dissolve it, followed by concentration. 4% aqueous NaHCO 3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na 2 SO 4 and concentrated. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.42 g), HONB (0.86 g) and DCC (0.99 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Ala-D-Asp(OBzl)-D-Leu-Leu-OPac (1.77 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-D-Asp(OBzl)-D-Leu-Leu-OPac (1.60 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OPac (1.47 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in ACOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Ala-Glu(OBzl)-D-Leu-Leu-OPac (1.81 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-Glu(OBzl)-D-Leu-Leu-OPac (1.63 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac (1.81 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac (1.63 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8-N HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Gly-Ala-D-Leu-Leu-OPac (2.23 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.55 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.22 g), HONB (0.71 g) and DCC (0.82 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac (2.51 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.96 g), HONB (0.59 g) and DCC (0.68 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D/Asp(OBzl)-Gly-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice.
  • HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • TFA (20 ml) was added to Boc-Ala-D-Leu-Leu-OPac (2.20 g) prepared in example 5 (1) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.61 ml) was added thereto.
  • Boc-Asp(OBzl)-ONB [prepared from Boc-Asp(OBzl)-OH (1.33 g), HONB (0.78 g) and DCC (0.89 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Asp(OBzl)-Ala-D-Leu-Leu-OPac (2.77 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.55 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.21 g), HONB (0.71 g) and DCC (0.81 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OPac (2.94 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.96 g), HONB (0.59 g) and DCC (0.68 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice.
  • HONB (0.16 g) and DCC (0.18 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-Glu(OBzl)-Ala-D-Leu-Leu-OPac (2.76 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.54 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.19 g), HONB (0.69 g) and DCC (0.80 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • TFA (20 ml) was added to Boc-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac (2.95 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.94 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice.
  • HONB (0.16 g) and DCC (0.18 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) prepared in example 1 (3) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Trp-ONB [prepared from Boc-Trp-OH (1.17 g), HONB (0.69 g) and DCC (0.79 g)] was added thereto, followed by stirring overnight.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Trp-Asp(OBzl)-D-Leu-Leu-OPac (2.31 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.75 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.96 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac (2.12 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto.
  • Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (3.92 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OH (0.56 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) prepared in example 1 (3) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Pro-ONB [prepared from Boc-Pro-OH (0.76 g), HONB (0.69 g) and DCC (0.79 g)] was added thereto, followed by stirring overnight.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Pro-Asp(OBzl)-D-Leu-Leu-OPac (2.07 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.75 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.96 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-Pro-Asp(0Bzl)-D-Leu-Leu-OPac (1.94 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.49 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OPac (1.39 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (3.92 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OH (0.53 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and benzylamine (1.09 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto.
  • Boc-Asn(CH 2 Ph)-ONB [prepared by catalytically reducing Boc-Asn(CH 2 Ph)-OBzl (1.23 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration.
  • Boc-Asn(CH 2 ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.92 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-Asn(CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.93 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac 500 mg was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.30 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OH (396 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and ⁇ -phenethylamine (0.79 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto.
  • Boc-Asn(CH 2 CH 2 Ph)-ONB [prepared by catalytically reducing Boc-Asn(CH 2 CH 2 Ph)-OBzl (1.28 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration.
  • Boc-Asn(CH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.95 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-Asn(CH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.95 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac 500 mg was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.28 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-OH (401 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and DMF (20 ml) containing tryptamine hydrochloride (0.98 ml) and TEA (1.04 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to obtain a desired product as a light yellow glassy material.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto.
  • Boc-Asn(CH 2 CH 2 -Ind)-ONB [prepared by catalytically reducing Boc-Asn(CH 2 CH 2 -Ind)-OBzl (1.35 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration.
  • Boc-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac 500 mg was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-OH (386 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.34 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10N-HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling.
  • Boc-Hys(Bzl)-ONB prepared from Boc-Hyp(Bzl)-OH (1.57 g), HONB (1.16 g) and DCC (1.55 g) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO 3 and a saturated aqueous solution of sodium chloride. After drying with Na 2 SO 4 , the solvent was removed by distillation, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The precipitate was recrystallized from AcOEt-petroleum.
  • Boc-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (3.49 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10-N HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling.
  • Boc-D-Asp(OBzl)-ONB prepared from Boc-D-Asp(OBzl)-OH (1.55 g), HONB (1.08 g) and DCC (1.44 g) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO 3 and a saturated aqueous solution of sodium chloride. After drying with Na 2 SO 4 , the solvent was removed by distillation, and the residue was purified by silica gel chromatography (Merck Kiesel Gel 60. 2% methanol/chloroform) to obtain an oily product.
  • Boc-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (3.77 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10-N HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling.
  • Boc-D-Trp-ONB prepared from Boc-D-Trp-OH (1.17 g), HONB (752 mg) and DCC (939 mg) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO 3 and a saturated aqueous solution of sodium chloride. After drying with Na 2 SO 4 , the solvent was removed by distillation, and the residue was purified by silica gel chromatography (Merck Kiesel Gel 60. 2% methanol/chloroform). Then, ether-petroleum ether was added thereto to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (2.52 g) was dissolved in 90% aqueous AcOH (50 ml), and Zn powder (6.54 g) was added thereto with stirring under ice cooling, further followed by stirring at room temperature. The Zn powder was removed by filtration, and filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na 2 SO 4 , the solvent was removed by distillation, and ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure.
  • Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OH (1.14 g) was dissolved in dichloromethane (10 ml), and HONB (358 mg) and DCC (413 mg) were successively added thereto with stirring under ice cooling, further followed by stirring under ice cooling for 3 hours.
  • the resulting insoluble material was removed by filtration, and the solvent was removed by distillation. The residue was dissolved in acetonitrile (20 ml), and the insoluble material was removed by filtration.
  • Boc-Asp(OBzl)-OH (32.3 g) and Cs 2 CO 3 (16.3 g) were dissolved in 90% aqueous methanol, and the solution was concentrated.
  • the residue was dissolved in DMF (300 ml), and phenacyl bromide (21.9 g) was added thereto, followed by stirring overnight.
  • the resulting CsBr was separated by filtration, and the filtrate was concentrated.
  • the residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO 3 and 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, the residue was recrystallized from ethyl acetate-petroleum ether.
  • Boc-Trp-OH (12.2 g) was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (4.4 ml) was added thereto, and subsequently, IBCF (5.4 ml) was added. After 2 minutes, a DMF solution of HCl.H-Asp(OBzl)-OPac and N-methylmorpholine was added.
  • HCl.H-Asp(OBzl)-OPac was obtained by dissolving Boc-Asp(OBzl)-OPac (17.7 g) in 8N-HCl/dioxane (100 ml), stirring the solution under ice cooling for 30 minutes, followed by concentration, and adding ether to precipitate crystals, which were collected by filtration and dried. After stirring at -15° C. for 30 minutes, the solution was brought to room temperature. After 30 minutes, the resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Trp-Asp(OBzl)-OPac 50.2 g
  • ether was added thereto to precipitate crystals, which were collected by filtration and dried.
  • the crystals were dissolved in DMF (80 ml), and the solution was cooled with ice, followed by addition of TEA (22.3 ml).
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (28.5 g), HONB (17.2 g) and DCC (19.8 g)] was added thereto, and the mixture was stirred overnight.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (23.8 g), HONB (15.3 g) and DCC (17.6 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Leu-ONB [prepared from Boc-Leu-OH.H 2 O (5.48 g), HONB (4.30 g) and DCC (4.95 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. The resulting residue was recrystallized from ethyl acetate-petroleum ether.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-tLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.75 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-tLeu-Leu-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.34 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D- ⁇ MeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.76 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D- ⁇ MeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.34 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.76 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.74 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.33 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated.
  • Boc-D-Asp(OBzl)-OH (25.0 g) was dissolved in methanol (50 ml), and Cs 2 CO 3 (12.6 g) was added thereto little by little with stirring at room temperature. After Cs 2 CO 3 was dissolved, the solvent was removed by distillation, and the residue was dissolved in DMF (500 ml). A DMF solution (50 ml) of phenacyl bromide (15.4 g) was added thereto dropwise with stirring under ice cooling, further followed by stirring at room temperature for 1 hour. Precipitated CsBr was removed by filtration,and the solvent was removed by distillation.
  • Boc-D-Asp(OBzl)-OPac (26.5 g) was dissolved in dioxane (50 ml), and 10N-HCl/dioxane (28.6 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to form a precipitate, which was collected by filtration, thereby obtaining H-D-Asp(OBzl)-OPac hydrochloride.
  • Boc-D-Trp-OH (18.3 g) was dissolved in distilled THF (150 ml), and N-methylmorpholine was added thereto with stirring at room temperature. After the atmosphere was replaced with nitrogen, isobutyl chloroformate (7.88 ml) was slowly added dropwise thereto with stirring at -15° C., and stirring was further continued at -15° C. for 15 minutes, thereby obtaining mixed acid anhydrides.
  • An amine component prepared by dissolving H-D-Asp(OBzl)-OPac hydrochloride in DMF (100 ml) and adding N-methylmorpholine (6.62 ml) thereto with stirring at -15° C.
  • Boc-D-Trp-D-Asp(OBzl)-OPac (34.5 g) was dissolved in dioxane (50 ml), and 10N-HCl/dioxane (100 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (350 ml), and TEA was added thereto with stirring under ice cooling to neutralize it.
  • Boc-Leu-D-Trp-D-Asp(OBzl)-OPac (29.6 g) was dissolved in dioxane (40 ml), and 10N-HCl/dioxane (100 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (300 ml), and TEA was added thereto with stirring under ice cooling to neutralize it.
  • Boc-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (17.1 g) was dissolved in dioxane (10 ml), and 10-N HCl/dioxane (50 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (100 ml), and TEA was added thereto with stirring under ice cooling to neutralize it.
  • Boc-Orn-OH (0.51 g) [obtained by catalytically reducing Boc-Orn(Z)-OH in methanol in a stream of hydrogen using 10% Pd-carbon as a catalyst] was dissolved in DMF, and the solution was cooled with ice.
  • TEA (0.61 ml) and PhCOONB [prepared from PhCOOH (0.30 g), HONB (0.47 g) and DCC (0.54 g)] were added thereto, followed by stirring overnight.
  • the reaction solution was concentrated, and the residue was dissolved in AcOEt.
  • the resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether and dicyclohexylamine (438 ⁇ l) were added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) obtained in (5) described above was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml).
  • Boc-Orn(COPh)-ONB [prepared from Boc-Orn(COPh)-OH (0.30 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.77 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours, Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice. TEA (1.53 ml) and PhCH 2 COCl (367 ⁇ l) was added thereto, and stirred for 2 hours. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether and cyclohexylamine (254 ⁇ l) were added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml).
  • Boc-Orn(COCH 2 Ph)-ONB [prepared from Boc-Orn(COCH 2 Ph)-OH (0.32 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.65 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.63 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice.
  • TEA (0.61 ml) and PhCH 2 CH 2 COONB [prepared from PhCH 2 CH 2 COOH (0.36 g), HONB (0.47 g) and DCC (0.54 g)] was added thereto, and stirred overnight.
  • the reaction solution was concentrated, and the residue was dissolved in AcOEt.
  • the resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether and dicyclohexylamine (438 ⁇ l) were added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml).
  • Boc-Orn(COCH 2 CH 2 Ph)-ONB [prepared from Boc-Orn(COCH 2 CH 2 Ph)-OH (0.33 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.78 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 CH 2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice.
  • TEA (0.61 ml) and Ind-CH 2 COONB [prepared from Ind-CH 2 COOH (0.42 g), HONB (0.47 g) and DCC (0.54 g)] was added thereto, and stirred overnight.
  • the reaction solution was concentrated, and the residue was dissolved in AcOEt.
  • the resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether and cyclohexylamine (254 ⁇ l) were added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml).
  • Boc-Orn(COCH 2 -Ind)-ONB [prepared from Boc-Orn(COCH 2 -Ind)-OH (0.35 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.80 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Orn(COCH 2 -Ind)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (20 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. The residue was purified using silica gel chromatography (1% methanol/DCM) and subsequently concentrated. The yield was 2.22 g (57.4%).
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Leu-ONB [prepared from Boc-Leu-OH.H 2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac (0.77 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Glu-OBzl (1.17 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.68 g) and DCC (0.79 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and benzylamine (0.76 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Gln(Bzl)-OH (3.36 g) [prepared by catalytically reducing Boc-Gln(Bzl)-OBzl (4.26 g) in methanol (20 ml) in a stream of hydrogen at ordinary temperature and pressure in the presence of 10% Pd-carbon (20 mg)] was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (1.1 ml) was added thereto, and subsequently, IBCF (1.3 ml) was added. After 2 minutes, a DMF solution of HCl.Asp(OBzl)-OPac and N-methylmorpholine (1.1 ml) was added.
  • HCl.Asp(OBzl)-OPac was obtained by dissolving Boc-Asp(OBzl)-OPac (4.41 g) in 8-N HCl/dioxane (50 ml), stirring the solution under ice cooling for 30 minutes, followed by concentration, and adding ether to precipitate crystals, which were collected by filtration and dried. After stirring at -15° C. for 30 minutes, the solution was brought to room temperature. After 30 minutes, the resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ethyl acetate was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-Leu-ONB [prepared from Boc-Leu-OH.H 2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac (0.78 g) was dissolved in 90% aqueous AcOH (15 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated.
  • Boc-Asp(ONB)-OBzl [prepared from Boc-Asp-OBzl (14.23 g), HONB (8.68 g) and DCC (9.99 g)] was added to tryptamine hydrochloride (7.87 g) together with TEA (8.4 ml) in DMF (150 ml) under ice-cooling, and the mixture was stirred overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to give crystals, which were collected by filtration.
  • Boc-Asn(CH 2 CH 2 -Ind)-OBzl (4.6 g) was dissolved in methanol (100 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in ether-AcOEt (1:1), and CHA (1.1 ml) was added thereto to precipitate crystals, which were collected by filtration. The crystals were recrystallized from methanol-ether to obtain a desired material.
  • Boc-Asn(CH 2 CH 2 -Ind)-OH [prepared from Boc-Asn(CH 2 CH 2 -Ind)-OH.CHA (3.7 g)] was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (0.9 ml) was added thereto, and subsequently, IBCF (1.1 ml) was added. After 2 minutes, a DMF solution of HCl.Asp(OBzl)-OPac and N-methylmorpholine was added.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with NagSO 4 and concentrated. Then, the residue was purified using silica gel chromatography (2% methanol/DCM). Subsequently, petroleum ether was added thereto to separate out a precipitate, which was collected by filtration.
  • Boc-Leu-ONB [prepared from Boc-Leu-OH.H 2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours.
  • the resulting insoluble material was separated by filtration, followed by concentration.
  • the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO 3 . After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-OPac (0.81 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na 2 SO 4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH 2 CH 2 -Ind)-Asp(OBzl)-OH (0.37 g) was dissolved in DCM (10 ml), and the solution was cooled with ice.
  • HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours.
  • the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration.
  • 8-N HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate.
  • Boc-Thg(2)-OH.CHA (17.8 g, 50 mmoles) was suspended in a mixed solvent of ethyl acetate (250 ml) and water (250 ml), followed by vigorous stirring. Then, 1N aqueous H 2 SO 4 (50 ml) was added thereto to dissolve it completely. The ethyl acetate layer was separated and dried with Na 2 SO 4 . The solvent was thereafter removed by evaporation under reduced pressure. DMF (90 ml) was added to the residue to prepare solution (I).
  • Tos.H-Leu-OBzl (39.4 g, 100 mmoles) was added to a mixed solvent of ethyl acetate (250 ml) and 10% aqueous NaHCO 3 (250 ml), followed by vigorous stirring to dissolve it completely. The ethyl acetate layer was separated and dried with Na 2 SO 4 . The solvent was thereafter removed by evaporation under reduced pressure. DMF (90 ml) was added to the residue to prepare solution (II).
  • DMF (100 ml) was added to the residue, and the solvent was removed by evaporation under reduced pressure. This operation was repeated twice. DMF (100 ml) was added to the residue to dissolve it, and 50 ml of a solution of phenacyl bromide (7.18 g, 35.0 mmoles) in DMF was added dropwise thereto under ice cooling for 10 minutes. The resulting mixture was brought to room temperature and then stirred overnight. The solvent was removed by distillation, and ethyl acetate was added to the residue, followed by extraction with ethyl acetate.
  • the ethyl acetate layer was separated and washed successively with 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO 3 and the saturated aqueous solution of NaCl. After drying with Na 2 SO 4 , the solvent was removed. Colorless crystals were obtained by crystallization from an ether-petroleum ether.
  • Boc-Asp(OBzl)-ONB [prepared from Boc-Asp(OBzl)-OH (9.68 g, 30 mmoles), HONB (5.91 g, 33.0 mmoles) and DCC (6.81 g, 33.0 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in ethyl acetate, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO 3 and the saturated aqueous solution of NaCl. After drying with Na 2 SO 4 , the solvent was removed by evaporation. Ether-petroleum ether was added to the residue to obtain a precipitate.
  • Boc-Asn(CH 2 CH 2 -Ind)-ONB [prepared from Boc-Asn(NHCH 2 CH 2 ind)-OH ⁇ prepared from Boc-Asn(NHCH 2 CH 2 Ind)-OH.CHA (14.5 g, 30.45 mmoles) ⁇ , HONB (5.72 g, 31.9 mmoles) and DCC (6.58 g, 31.9 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. Ethyl acetate-ether (1:1) was added to the residue to obtain a precipitate.
  • Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (8.82 g, 27.3 mmoles), HONB (5.12 g, 28.6 mmoles) and DCC (5.90 g, 28.6 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. The residue was dissolved in ethyl acetate, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO 3 and the saturated aqueous solution of NaCl. After drying with Na 2 SO 4 , the solvent was removed by evaporation. Ethyl acetate-ether was added to the residue to obtain a precipitate.
  • Boc-D-Trp-ONB prepared from Boc-D-Trp-OH (6.70 g, 22.0 mmoles), HONB (4.34 g, 24.2 mmoles) and DCC (5.00 g, 24.2 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue.
  • the residue was dissolved in chloroform, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO 3 and the saturated aqueous solution of NaCl. After drying with Na 2 SO 4 , the solvent was removed by evaporation. The residue was purified by silica gel column chromatography (9.5 cm ⁇ 50 cm, 0.5% methanol-chloroform). Ether-petroleum ether was added to the purified product to obtain a precipitate.
  • a membrane fraction prepared from the porcine heart was diluted to 0.15 mg/ml by using a buffer solution for assay, and 100 ⁇ l of the resulting suspension of the membrane fraction was poured into each assay tube to use for assay.
  • To this suspension of the membrane fraction was added 2 ⁇ l of 5 nM 125 I-labeled endothelin-1 solution. Further, 3 ⁇ l of a test peptide solution was added thereto, followed by incubation at a temperature of 25° C. for 1 hour. Then, the resulting suspension was diluted with 900 ⁇ l of the buffer solution for assay cooled with ice, and thereafter separated into a supernatant and a precipitate by centrifugation at 12,000 ⁇ g for 10 minutes.
  • the numerical value of ET A shown in Table 1 is the value of specific activity, taking the binding activity of this cyclic pentapeptide on the receptor A as 1.0.
  • the binding activity (IC 50 ) of this cyclic pentapeptide on the ET A receptor is 2 ⁇ 10 -6 M.
  • a membrane fraction prepared from the bovine brain was diluted to 0.15 mg/ml by using a buffer solution for assay, and 100 ⁇ l of the resulting suspension of the membrane fraction was poured into each assay tube to use for assay.
  • To this suspension of the membrane fraction was added 2 ⁇ l of 5 nM 125 I labeled endothelin-1 solution. Further, 3 ⁇ l of a test peptide solution was added thereto, followed by incubation at a temperature of 25° C. for 1 hour. Then, the resulting suspension was diluted with 900 ⁇ l of the buffer solution for assay cooled with ice, and thereafter separated into a supernatant and a precipitate by centrifugation at 12,000 ⁇ g for 10 minutes.
  • the binding activity (IC 50 ) of the compound of Example 8 on the ET B receptor is 3 ⁇ 10 -6 M.
  • guinea pigs' kidneys were used.
  • Guinea pigs (Std Hartrey, male 250 g, Japan SLC Ltd.) were made to have a cerebral concussion and sacrificed by bleeding from carotid arteries to pick up the kidneys and removed fat therefrom to prepare the kidneys.
  • the obtained kidneys were sliced and homogenized by politron homogenizer in 20 ml of 50 mM Tris-HCl buffer [pH 7.4; 20 mM NaHCO 3 , 0.1 mM PMSF (Phenylmethylsulfonyl Fluoride), 1 mM EDTA (Ethylenediaminetetraacetic acid)] per one kidney.
  • Tris-HCl buffer pH 7.4; 20 mM NaHCO 3 , 0.1 mM PMSF (Phenylmethylsulfonyl Fluoride), 1 mM EDTA (Ethylenediaminetetraacetic acid)
  • the homogenized kidney was applied to a centrifugation at 1,000 ⁇ g for 15 minutes and the supernatant was further applied to a centrifugation for 20 minutes at 30,000 ⁇ g.
  • the resulting precipitate was twice washed with 50 mM Tris-HCl buffer (pH 7.4) containing 0.1 mM PMSF, 1 mM EDTA.
  • the resultant was stored at -80 ° C. as a crude receptor membrane fraction and was used as the suspension in the following buffer when necessary.
  • the reaction was stopped by fast filtration on a glass filter (GF/B, Wattman, USA) by Cell Harvestor (290 PHD, Cambridge-Technology, Great Britain), and the filter was three times washed with 50 mM Tris-HCl buffer (pH 7.4). Radio activity remained on the filter was assayed by a gamma counter.
  • the inner wall of the bovine third stomach stored at -80° C. was cut to 1 cm ⁇ 1 cm or less, and disrupted in 3 liters/kg of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 120 mM sodium chloride, 5 mM potassium chloride, 0.02% BSA and 5% sucrose, using a polytron homogenizer (Kinematika, Germany). Then, the disrupted product was centrifuged at 1,000 ⁇ g for 10 minutes. The supernatant was further centrifuged at 45,000 ⁇ g for 20 minutes.
  • the precipitate was suspended in 200 ml of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 300 mM potassium chloride, 10 mM ethylenediaminetetraacetic acid, 0.1 mM phenylmethylsulfonium fluoride and 0.02% BSA, and gently stirred under ice cooling for 60 minutes. The suspension was centrifuged at 45,000 ⁇ g for 20 minutes. The precipitate was washed with 200 ml of 50 mM Tris-HCl buffer (pH 7.4), and stored in the frozen state at -40° C. as a receptor sample.
  • reaction buffer solution [50 mM Tris-HCl buffer (pH 7.4), 0.02% bovine serum albumin and 4 mM manganese chloride] so as to give a protein concentration of 0.7 mg/ml, and 100 ⁇ l thereof was used for reaction.
  • a test sample and 125 I-NKA (0.61 KBq, 125 I-neurokinin A, 81.4 TBq/mmol, Du Pont/NEN Research Products, U.S.A.) were also added, and reacted in 0.2 ml of the reaction buffer solution at 25° C. for 3 hours.
  • the reaction mixture was rapidly filtered through a glass filter (GF/B, Whatman, U.S.A.) using a cell harvester (Type 290PHD, Cambridge Technology Inc.) to terminate the reaction, and washed 3 times with 250 ⁇ l of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 0.02% bovine serum albumin.
  • the radioactivity left on the filter was measured with a gamma-ray counter. Results are shown in Table 1 as the binding inhibiting activity (IC 50 , unit: ⁇ M) on the NK2 receptor.

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Abstract

Cyclic peptides and their salts have antagonistic activity on endothelin receptors and antagonistic activity on NK2 receptors. The peptides have the formula ##STR1## wherein X and Y each represent α-amino acid residues, A represents a D-acidic-α-amino acid residue, B represents a neutral α-amino acid residue, C represents an L-α-amino acid residue and D represents a D-α-amino acid residue having an aromatic ring group; wherein hydroxy, thiol, amino, imino and carboxyl groups can be substituted or unsubstituted. Pharmaceutical compositions containing such peptides are also described.

Description

This is a continuation of application Ser. No. 07/927,205 filed on Aug. 7, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to novel cyclic peptides having antagonistic activity on endothelin receptors and antagonistic activity on NK2 receptors. These cyclic peptides are useful as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases, renal diseases and asthma, anti-inflammatory drugs, antarthritics and the like. The present invention further relates to the use thereof.
Endothelin (ET) is a vasoconstrictive peptide composed of 21 amino acid residues. Endothelin was isolated from the culture supernatant of the endothelial cells of porcine aortas. Its structure was determined by M. Yanagisawa et al. in 1988 [M. Yanagisawa et al., Nature 332, 411-412 (1988)]. More recently, the research on genes coding for endothelin revealed the presence of peptides similar to endothelin in structure. These peptides are named endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3), respectively. Their structures are as follows:
______________________________________                                    
H--Cys--Al--Cys-A2-A3-A4-A5-                                              
Asp--Lys--Glu--Cys--Val--Tyr-A6-                                          
Cys--His--Leu--Asp--Ile--Ile--Trp--OH                                     
             A1   A2     A3     A4   A5   A6                              
______________________________________                                    
ET-1 SEQ ID NO 1   Ser    Ser  Ser  Leu  Met  Phe                         
ET-2 SEQ ID NO 2   Ser    Ser  Ser  Trp  Leu  Phe                         
ET-3 SEQ ID NO 3   Thr    Phe  Thr  Tyr  Lys  Tyr                         
______________________________________
All of the amino acids constituting ET-1, ET-2 and ET-3 take the L-form [Inoue et al., Proc. Natl. Acad. Sci. U.S.A. 86, 2863-2867 (1989)].
The above-mentioned peptides of the endothelin family exist in vivo and have vasopressor activity. For this reason, these peptides are anticipated to be intrinsic factors responsible for the control of circulatory systems, and deduced to be related to hypertension, cardiac or cerebral circulatory diseases such as cardiac infarction and renal diseases such as acute renal insufficiency. In addition, these peptides also have bronchial smooth muscle constrictor activity, and therefore deduced to be related to asthma.
If antagonists to the receptors of the above-mentioned peptides of the endothelin family are obtained, they are not only considered to be useful for elucidation of the functional mechanism of these peptides, but also likely to be used as effective therapeutic drugs for the above-mentioned diseases. We already filed applications for patents with respect to fermentation product-derived cyclic pentapeptides having the antagonistic activity on the endothelin receptors (Japanese Patent Application Nos. 2-413828/1990 and 3-126160/1991). It is therefore an object of the present invention to provide novel peptides which are effective similarly or more than the peptides previously filed.
SUMMARY OF THE INVENTION
The present inventors prepared novel cyclic peptides having the antagonistic activity on the endothelin receptors, and further discovered that a certain group of the peptides thus obtained had the antagonistic activity on the NK2 receptors, completing the present invention by further studies.
Namely, the present invention provides
(1) a cyclic hexapeptide represented by formula [I] or a salt thereof: ##STR2## wherein X and Y each represents α-amino acid residues, A represents a D-acidic-α-amino acid residue, B represents a neutral-α-amino acid residue, C represents an L-α-amino acid residue and D represents a D-α-amino acid residue having an aromatic ring group; and
(2) a pharmaceutical composition comprising the peptide represented by formula [I] or a pharmaceutically acceptable salt thereof as an active ingredient, in for example, an endothelin receptor antagonist effective amount or an NK2 receptor antagonist effective amount.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hexapeptide represented by formula [I] has 6 amide bonds including a bond between A and D, thereby showing that the molecule forms a ring as a whole. In this specification, this hexapeptide is sometimes referred to as cyclo[-A-X-Y-B-C-D-].
In formula [I], an amino acid which forms the α-amino acid residue represented by X or Y may be any amino acid as long as it is an α-amino acid. Examples thereof include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, 2-aminomalonic acid, 2-aminoadipic acid, glycine, histidine, isoleucine, leucine, lysine, ornithine, 2,4-diaminobutyric acid, methionine, phenylalanine, proline, 4-hydroxyproline, thioproline, azetidine-2-carboxylic acid, pipecolic acid (piperidine-2-carboxylic acid), indoline-2-carboxylic acid, tetrahydroisoquinoline-3-carboxylic acid, serine, threonine, tryptophan, 5-methyltryptophan, tyrosine, valine, alloisoleucine, norvaline, norleucine, tertiary leucine, γ-methylleucine, phenylglycine, 2-aminobutyric acid, cysteic acid, homocysteic acid, 1-naphthylalanine, 2-naphthylalanine, 2-thienylglycine, 3-thienylglycine, 3-benzothienyl-alanine, 4-biphenylalanine, pentamethylphenylalanine, 1-aminocyclopropane-1-carboxylic acid, 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, 1-aminocyclohexane-1-carboxylic acid and 1-aminocycloheptane-1-carboxylic acid. When these α-amino acids have functional groups such as hydroxyl, thiol, amino, imino and carboxyl, these functional groups may be substituted.
The substituted hydroxyl groups include esters such as C1-6 fatty acid esters (for example, formates, acetates and propionates), C4-9 alicyclic carboxylic acid esters (for example, cyclopentanecarboxylates and cyclohexanecarboxylates), C7-15 arylcarboxylic acid esters (for example, benzoates and 4-methylbenzoates), C8-16 aralkylcarboxylic acid esters (for example, phenylacetates, 2-phenylpropionates, 3-phenylpropionates and diphenylacetates) and aromatic heterocycle-alkylcarboxylic acid esters (for example, indole-2-ylacetates and indole-3-ylacetates); and ethers such as C1-6 alkyl ethers (for example, methyl ethers, ethyl ethers, n-propyl ethers and t-butyl ethers), C3-8 cycloalkyl ethers (for example, cyclopentyl ethers and cyclohexyl ethers), C6-12 aryl ethers (for example, phenyl ethers and 4-methylphenyl ethers) and C7-15 aralkyl ethers (for example, benzyl ethers, phenethyl ethers and diphenylmethyl ethers). Examples of the α-amino acids whose hydroxyl groups are substituted include O-acetylserine, O-acetylthreonine, 4-acetoxyproline, O-benzoylserine, O-benzoylthreonine, 4-benzoyloxyproline, O-phenylacetylserine, O-phenylacetylthreonine, 4-phenylacetoxyproline, O-ethylserine, O-ethylthreonine, 4-ethoxyproline, O-cyclohexylserine, O-cyclohexylthreonine, 4-cyclohexyloxyproline, O-phenylserine, O-phenylthreonine, 4-phenoxyproline, O-benzylserine, O-benzylthreonine, 4-benzyloxyproline, O-diphenylmethylserine, O-diphenylmethylthreonine and 4-diphenylmethoxyproline.
The substituted thiol groups include thiol esters such as C1-6 fatty acid thiol esters (for example, formic acid thiol esters, acetic acid thiol esters and propionic acid thiol esters), C4-9 alicyclic carboxylic acid thiol esters (for example, cyclopentanecarboxylic acid thiol esters and cyclohexanecarboxylic acid thiol esters), C7-15 arylcarboxylic acid thiol esters (for example, benzoic acid thiol esters and 4-methylbenzoic acid thiol esters) and C8-16 aralkylcarboxylic acid thiol esters (for example, phenylacetic acid thiol ester, 2-phenylpropionic acid thiol esters, 3-phenylpropionic acid thiol esters and diphenylacetic acid thiol esters); and thioether forms such as C1-6 alkyl thioethers (for example, methyl thioethers, ethyl thioethers, n-propyl thioethers and t-butyl thioethers), C3-8 cycloalkyl thioethers (for example, cyclopentyl thioethers and cyclohexyl thioethers), C6-12 aryl thioethers (for example, phenyl thioethers and 4-methylphenyl thioethers) and C7-15 aralkyl thioethers (for example, benzyl thioethers, phenethyl thioethers and diphenylmethyl thioethers). Examples of the α-amino acids whose thiol groups are substituted include S-acetyl-cysteine, S-benzoylcysteine, S-phenylacetylcysteine, S-ethylcysteine, S-cyclohexylcysteine, S-phenylcysteine and S-benzylcysteine.
The substituted amino groups (or imino groups) include substituted amino or imino groups such as C1-6 alkylamino (or imino) [for example, N-methylamino (or imino), N-ethylamino (or imino) and N-t-butylamino (or imino)], C3-8 cycloalkyl-amino (or imino) [for example, N-cyclopentylamino (or imino) and N-cyclohexylamino (or imino)], C6-12 arylamino (or imino) [for example, N-phenylamino (or imino) and N-{4-methylphenyl}amino (or imino)], C7-15 aralkylamino (or imino) [for example, N-benzylamino (or imino), N-phenethyl-amino (or imino), N-{2-chlorobenzyl}amino (or imino), N-{3-chlorobenzyl}amino (or imino), N-{4-chlorobenzyl}amino (or imino), N-{2-methylbenzyl}amino (or imino), N-{3-methyl-benzyl}amino (or imino), N-{4-methylbenzyl}amino (or imino), N-{2-methoxybenzyl}amino (or imino), N-{3-methoxy-benzyl}amino (or imino) and N-{4-methexybenzyl}amino (or imino)] and aromatic heterocycle-C1-5 alkylamino (or imino) [for example, 2-furylmethylamino (or imino), 3-furyl-methylamino (or imino), 2-thienylmethylamino (or imino), 3-thienylmethylamino (or imino), indole-2-ylmethylamino (or imino) and indole-3-ylmethylamino (or imino)]; and substituted amido (or imido) groups such as C1-6 aliphatic acylamido (or imido) [for example, formamido (or imido), acetamido (or imido) and propionamido (or imido)], C4-9 alicyclic acylamido (or imido) [for example, cyclopentanecarbonylamido (or imido) and cyclohexanecarbonylamido (or imido)], C7-15 arylacylamido (or imido) [for example, benzamido (or imido) and 4-methylbenzamido (or imido)], C8-16 aralkylacylamido (or imido) [for example, phenylacetamido (or imido), 2-phenylpropionamido (or imido), 3-phenylpropionamido (or imido), diphenylacetamido (or imido), 1-naphthylacetamido (or imido) and 2-naphthylacetamido (or imido)], aromatic heterocycle-carbonylamido (or imido) [for example, indole-2-ylcarbonylamido (or imido) and indole-3-ylcarbonylamido (or imido)], aromatic heterocycle-alkylcarbonylamido (or imido) [for example, indole-2-ylacetamido (or imido) and indole-3-ylacetamido (or imido)], and sulfonylamido (or imido) [for example, benzenesulfonylamido (or imido), p-toluenesulfonylamido (or imido) and 4-methoxy-2,3,6-trimethylbenzenesulfonylamido (or imido)]. Examples of the α-amino acids whose amino (or imino) groups are substituted include N-methylglycine (sarcosine), N-ethylglycine, N-methylleucine, N-ethylleucine, N-methylphenylalanine, N-ethylphenylalanine, N(α)-methyltryptophan, N(α)-ethyltryptophan, N-cyclopentylglycine, N-cyclohexylglycine, N-phenylglycine, N-phenylleucine, N-benzylglycine, N-benzylleucine, N(π)-benzylhistidine, N(τ)-benzylhistidine, N(π)-phenacylhistidine, N(π)-benzyloxymethylhistidine, Ng -benzenesulfonylarginine, Ng -p-toluenesulfonylarginine, Ng -(4-methoxy-2,3,6-trimethylbenzenesulfonyl)arginine, N(.di-elect cons.)-benzenesulfonyllysine, N(.di-elect cons.)-p-toluenesulfonyllysine, N(.di-elect cons.)-(4-methoxy-2,3,6-trimethylbenzenesulfonyl)lysine, Nin -methyltryptophan, Nin -ethyltryptophan, Nin -formyltryptophan, Nin -acetyltryptophan, N(.di-elect cons.)-benzyllysine, N(.di-elect cons.)-(2-furylmethyl)lysine, N(.di-elect cons.)-(2-thienylmethyl)lysine, N(.di-elect cons.)-(indole-3-ylmethyl)lysine, N(.di-elect cons.)-phenylacetyllysine, N(.di-elect cons.)-({2-furyl}acetyl)lysine, N(.di-elect cons.)-({2-thienyl}acetyl)lysine, N(.di-elect cons.)-({indole-3-yl}acetyl)lysine, N(.di-elect cons.)-benzoyllysine, N(.di-elect cons.)-(3-phenylpropionyl)lysine, N(δ)-benzylornithine, N(δ)-(2-furylmethyl)ornithine, N(δ)-(2-thienylmethyl)ornithine, N(δ)-(indole-3-ylmethyl)ornithine, N(δ)-benzoylornithine, N(δ)-phenylacetylornithine, N(δ)-(3-phenylpropionyl)ornithine, N(δ)-({2-methylphenyl}acetyl)ornithine, N(δ)-({3-methylphenyl}acetyl)ornithine, N(δ)-({4-methylphenyl}acetyl)ornithine, N(δ)-({2-chlorophenyl}acetyl)ornithine, N(δ)-({3-chlorophenyl}acetyl)ornithine, N(δ)-({4-chlorophenyl}acetyl)ornithine, N(δ)-({2-methoxyphenyl}acetyl)ornithine, N(δ)-({3-methoxyphenyl}acetyl)ornithine, N(δ)-({4-methoxyphenyl}acetyl)ornithine, N(δ)-(4-biphenylacetyl)ornithine, N(γ)-benzyl-2,4-diaminobutyric acid, N(γ)-(2-furylmethyl)-2,4-diaminobutyric acid, N(γ)-(2-thienylmethyl)-2,4-diaminobutyric acid, N(γ)-(indole-3-ylmethyl)-2,4-diaminobutyric acid, N(γ)-benzoyl-2,4-diaminobutyric acid, N(γ)-phenylacetyl-2,4-diaminobutyric acid, N(γ)-(3-phenylpropionyl-2,4-diaminobutyric acid, N(γ)-(2-furylacetyl)-2,4-diaminobutyric acid, N(γ)-(2-thienylacetyl)-2,4-diaminobutyric acid and N(γ)-({inole-3-yl}acetyl)-2,4-diaminobutyric acid.
The substituted carboxyl groups include amido groups such as carboxylic acid amido (--CONH2), N--C1-6 alkylamido (for example, N-methylamido, N-ethylamido, N-{n-propyl}amido and N-t-butylamido), N--C3-8 cycloalkylamido (for example, N-cyclopentylamido and N-cyclohexylamido), N--C6-12 arylamido (for example, N-phenylamido and N-{4-methylphenyl}amido), N--C7-15 aralkylamido (for example, N-benzylamido, N-phenethylamido, N-{1,2-diphenylethyl}amido), N-{aromatic heterocycle-C1-6 alkyl}amido (for example, N-[2-{indole-2-yl}ethyl]amido and N-[2-{indole-3-yl}ethyl]amido), piperidineamido, piperazineamido, N4 --C1-6 alkylpiperazineamido (for example, N4 -methylpiperazineamido and N4 -ethylpiperazineamido), N4 --C3-8 cycloalkylpiperazineamido (for example, N4 -cyclopentylpiperazineamido and N4 -cyclohexylpiperazineamido), N4 -(5 to 7 membered heterocyclicpiperazineamido (for example N4 -pyridylpiperazineamido, N4 -furylpiperazineamido, N4 -thienylpiperazineamido), N4 --C6-12 arylpiperazineamido (for example, N4 -phenylpiperazineamido and N4 -{4-methylphenyl}piperazineamido), N4 --C7-15 aralkylpiperazineamido (for example, N4 -benzylpiperazineamido, N4 -phenetylpiperazineamido, N4 -{1,2-diphenylethyl}piperazineamido), N4 -{aromatic heterocycle-C1-6 alkyl}piperazineamido (for example, N4 -[2-{indole-2-yl}ethyl]piperazineamido and N4 -[2-{indole-3-yl}ethyl]piperazineamido), N4 --C1-6 aliphatic acylpiperazineamido (for example, N4 -acetylpiperazineamido and N4 -propionylpiperazineamido), N4 --C4-9 alicyclic acylpiperazineamido (for example, N4 -cyclopentanecarbonylpiperazineamido and N4 -cyclohexanecarbonylpiperazineamido), N4 --C7-15 arylacylpiperazineamido (for example, N4 -benzoylpiperazineamido and N4 -{4-methylbenzoyl}piperazineamido), N4 --C8-16 aralkylacylpiperazineamido (for example, N4 -phenylacetylpiperazineamido N4 -{2-phenylpropion}piperazineamido, N4 -{3-phenylpropionyl}piperazineamido, N4 -diphenylacetylpiperazineamido), N4 -{1-naphthylacetyl}piperazineamido and N4 -{2-naphthylacetyl}piperazineamido), N4 -{aromatic heterocycle-carbonyl}piperazineamido (for example, N4 -{indole-2-ylcarbonyl}piperazineamido and N4 -{indole-3-ylcarbonyl}piperazineamido), and N4 -{aromatic heterocyclicalkylcarbonyl}piperazineamido (for example, N4 -{indole-2-ylacetyl}piperazineamido and N4 -{indole-3-ylacetyl}piperazineamido); and esters such as C1-6 alkyl esters (for example, methyl esters, ethyl esters and n-propyl esters), C3-8 cycloalkyl esters (for example, cyclopentyl esters and cyclohexyl esters) and C7-15 aralkyl esters (for example, benzyl esters, phenetyl esters, 1-phenylethyl esters and diphenylmethyl esters). The above-mentioned amido forms also include amido groups with α-amino acids and amido groups with oligopeptides (for example, dipeptides, tripeptides and tetrapeptides). The α-amino acids whose carboxyl groups are substituted include, for example, N4 -methylasparagine, N4 -phenylasparagine, N4 -benzylasparagine, N4 -phenethylasparagine, N4 -(2-{indole-3-yl}ethyl)asparagine, N5 -methylglutamine, N5 -phenylglutamine, N5 -benzylglutamine, N5 -phenethylglutamine, N5 -(2-{indole-3-yl}ethyl)glutamine, aspartic acid β-methyl ester, aspartic acid β-cyclopropyl ester, aspartic acid β-benzyl ester, aspartic acid β-phenethyl ester, aspattic acid β-N4 -phenylpiperazineamide, aspartic acid β-N4 -(2-methylphenyl)piperazineamide, aspartic acid β-N4 -(3-methylphenyl)piperazineamide, aspartic acid β-N4 -(4-methylphenyl)piperazineamide, aspartic acid β-N4 -(2-methoxyphenyl)piperazineamide, aspartic acid β-N4 -(3-methoxyphenyl)piperazineamide, aspartic acid β-N4 -(4-methoxyphenyl)piperazineamide, aspartic acid β-N4 -(2-chlorophenyl)piperazineamide, aspartic acid β-N4 -(3-chlorophenyl)piperazineamide, aspartic acid β-N4 -(4-chlorophenyl)piperazineamide, aspartic acid β-N4 -(4-nitrophenyl)piperazineamide, aspartic acid β-N4 -(4-fluorophenyl)piperazineamide, aspartic acid β-N4 -(3-trifluoromethylphenyl)piperazineamide, aspartic acid β-N4 -(2,3-dimethylphenyl)piperazineamide, aspartic acid β-N4 -(2-pyridyl)piperazineamide, aspartic acid β-N4 -(2-pyrimidyl)piperazineamide, glutamic acid γ-methyl ester, glutamic acid γ-cyclopropyl ester, glutamic acid γ-benzyl ester and glutamic acid γ-phenethyl ester.
The α-amino acid which forms the amino acid residue represented by X or Y in formula [I] may be any of the L-, D- and DL-forms. The L-form is, however, more preferred in each case.
An amino acid which forms the D-acidic-α-amino acid residue represented by A in formula [I] is, for example, an amino acid with an acidic group such as carboxyl, sulfonyl or tetrazolyl as a side chain. Examples of such amino acids include D-glutamic acid, D-aspartic acid, D-cysteic acid, D-homocysteic acid, D-β-(5-tetrazolyl)alanine and D-2-amino-4-(5-tetrazolyl)butyric acid. In particular, D-glutamic acid, D-aspartic acid and D-cysteic acid are preferred.
An amino acid which forms the neutral-α-amino acid residue represented by B in formula [I] is an α-amino acid. Examples of such α-amino acids include alanine, valine, norvaline, leucine, isoleucine, alloisoleucine, norleucine, tertiary leucine, γ-methylleucine, phenylglycine, phenylalanine, 1-naphthylalanine, 2-naphthylalanine, proline, 4-hydroxyproline, azetidine-2-carboxylic acid, pipecolic acid (piperidine-2-carboxylic acid), 2-thienylalanine, 2-thienylglycine, 3-thienylglycine, 1-aminocyclopropane-1-carboxylic acid, 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, 1-aminocyclohexane-1-carboxylic acid, 1-aminocycloheptane-1-carboxylic acid, 2-cyclopentylglycine and 2-cyclohexylglycine. When the above-mentioned neutral-α-amino acid exists in the L- and D-forms, the D-form is preferred. D-Leucine, D-alloisoleucine, D-tertiary leucine, D-γ-methylleucine, D-phenylglycine, D-2-thienylalanine, D-2-thienylglycine, D-3-thienylglycine and D-2-cyclopentylglycine are preferred among others. α-Imino groups of these neutral-α-amino acids may be substituted by C1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl). Examples of such α-amino acids include N-methylleucine, N-methylalloisoleucine, N-methyl tertiary leucine, N-methyl γ-methylleucine and N-methylphenyl-glycine. Also for these α-amino acids, the D-form is preferred.
As an amino acid which forms the L-α-amino acid residue represented by C in formula [I], used is an L-α-amino acid usually known in the art. Examples of such L-α-amino acids include glycine, L-alanine, L-valine, L-norvaline, L-leucine, L-isoleucine, L-tertiary leucine, L-norleucine, L-methionine, L-2-aminobutyric acid, L-serine, L-threonine, L-phenylalanine, L-aspartic acid, L-glutamic acid, L-asparagine, L-glutamine, L-lysine, L-tryptophan, L-arginine, L-tyrosine and L-proline. In particular, L-leucine, L-norleucine and L-tryptophan are preferred. α-Imino groups of these L-α-amino acids may be substituted by C1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl). Examples of such L-α-amino acids include L-N-methylleucine, L-N-methylnorleucine and L-N(α)-methyltryptophan.
As an amino acid which forms the D-α-amino acid residue with the aromatic ring group represented by D in formula [I], used is a D-α-amino acid having an aromatic ring group as a side chain. Preferred examples thereof include D-tryptophan, D-5-methyltryptophan, D-phenylalanine, D-tyrosine, D-1-naphthylalanine, D-2-naphthylalanine, D-3-benzothienylalanine, D-4-biphenylalanine and D-pentamethylphenylalanine. D-Tryptophan and D-5-methyltryptophan are preferred, and particularly, D-tryptophan is more preferred. The α-imino groups of the D-α-amino acids having the aromatic rings may be substituted by C1-6 alkyl groups (for example, methyl, ethyl, n-propyl and t-butyl). Further, the imino group of the indole ring of D-tryptophan may be substituted by a hydrocarbon group such as a C1-6 alkyl group (for example, methyl, ethyl, n-propyl or t-butyl), a C3-8 cycloalkyl group (for example, cyclopentyl or cyclohexyl), a C6-12 aryl group (for example, phenyl, or 4-methylphenyl) or C7-15 aralkyl (for example, benzyl or phenethyl), or an acyl group such as a C1-6 aliphatic acyl group (for example, formyl, acetyl or propionyl), a C4-9 alicyclic acyl group (for example, cyclopentanecarbonyl or cyclohexanecarbonyl), a C7-15 arylacyl group (for example, benzoyl or 4-methylbenzoyl), a C8-16 aralkylacyl group (for example, phenylacetyl, 2-phenylpropionyl, 3-phenylpropionyl or diphenylacetyl) or a C1-6 alkoxycarbonyl group (for example, methoxycarbonyl or ethoxycarbonyl). Examples of such α-amino acids include D-N(α)-methyltryptophan, D-N-methylphenylalanine, D-N-methyltyrosine, D-Nin -methyltryptophan, D-Nin -ethyltryptophan, D-Nin -formyltryptophan and D-Nin -acetyltryptophan. D-Nin -methyltryptophan, D-Nin -formyltryptophan and D-Nin -acetyltryptophan are preferred among others.
In the hexapeptide represented by formula [I], the preferable embodiments of each parameter are as follows:
X has L-configuration.
Y has L-configuration.
A is selected from the group consisting of D-glutamic acid, D-aspartic acid, D-cysteic acid and D-β-(5-tetrazolyl)alanine residue.
B has D-configuration.
B is selected from the group consisting of 1-aminocyclopropane-1-carboxylic acid, 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, 1-aminocyclohexane-1-carboxylic acid and 1-aminocycloheptane-1-carboxylic acid residue.
B is selected from the group consisting of D-leucine, D-alloisoleucine, D-tertiaryleucine, D-gammamethylleucine, D-phenylglycine, D-2-thienylglycine, D-3-thienylglycine, D-cyclopentylglycine, D-phenylalanine, D-2-thienylalanine, D-valine, D-2-furylhglycine and D-3-furylglycine residue.
C is selected from the group consisting of L-leucine, L-isoleucine, L-valine, L-norleucine and L-α-amino acid residue having aromatic moiety.
C is selected from the group consisting of L-leucine, L-phenylalanine and L-tryptophan.
D is D-tryptophan, or a derivative thereof, D-1-naphthylalanine, D-2-naphthylalanine, D-benzothienylalanine, D-4-bisphenylalanine and D-pentamethylphenylalanine residue.
The derivative of tryptophan is selected from the group consisiting of D-Nin -methyltryptophan, D-Nin -formyltryptophan and D-Nin -acetyltryptophan residue.
Preferable combinations of each parameter include such as those in which A is D-aspartic acid residue; X is tryptophan, L-(β-4-phenylpiperazine amide)aspartic acid, L-(N.sup.δ -phenylacetyl)ornithine, L-(N4 -[indol-3-yl]ethyl)ornithine, L-(4-benzyloxy)proline, L-(N5 -benzyl)glutamine or L-(N.sup.δ -[indol-3-yl]acetyl)asparagine residue; Y is L-leucine, L-aspartic acid, L-O-benzylserine, tryptophan, serine or proline residue; B is D-leucine, D-2-thienylglycine or D-3-thienylglycine residue; C is L-leucine residue; and D is D-tryptophan residue.
All the cyclic peptides represented by formula [I] of the present invention (hereinafter referred to as the cyclic peptides [I]) have the antagonistic activity on endothelin receptors. In addition, the peptides having amino acid residues such as aspartic acid and tryptophan as X and amino acid residues such as leucine, tryptophan and O-benzylserine as Y further also have the antagonistic activity on NK2 receptors.
The salts of the cyclic peptides [I] include metal salts (for example, sodium salts, potassium salts, calcium salts and magnesium salts), salts of bases or basic compounds (for example, ammonium salts and arginine salts), addition salts of inorganic acids (for example, hydrochlorides, sulfates and phosphates), and salts of organic acids (for example, acetates, propionates, citrates, tartarates, malates and oxalates).
As described in the working examples of the specification, the cyclic peptides [I] of the present invention can be produced by methods for peptide synthesis known in the art, which may be either solid phase synthesis methods or liquid phase synthesis methods. In some cases, the liquid phase synthesis methods are preferred. Examples of such methods for peptide synthesis include methods described in M. Bodansky and M. A. Ondetti, Peptide Synthesis., Interscience, New York (1966); F. M. Finn and K. Hofmann, The Proteins, Vol. 2, edited by H. Nenrath and R. L. Hill, Academic Press, New York, (1976); N. Izumiya et al., Peptide Gosei no Kiso to Jikken (Fundamentals and Experiments of Peptide Synthesis), Maruzen (1985); H. Yazima, S. Sakakibara et al., Seikagaku Jikken Koza (Course of Biochemical Experiments), 1, edited by Biochemical Society of Japan, Tokyo Kagaku Dojin (1977); H. Kimura et al., Zoku Seikagaku Jikken Koza (Course of Biochemical Experiments, second series), 2, edited by Biochemical Society of Japan, Tokyo Kagaku Dojin (1987); and J. M. Stewart and J. D. Young, Solid Phase Peptide Synthesis, Pierce Chemical Company, Illinois (1984), which describe azide methods, chloride methods, acid anhydride methods, mixed acid anhydride methods, DCC methods, active ester methods, methods using Woodward reagent K, carbodiimidazole methods, oxidation-reduction methods, DCC/HONB methods and methods using BOP reagents.
The cyclic peptide [I] of the present invention can be produced by condensing a first starting material having a reactive carboxyl group corresponding to one of two kinds of fragments which are separated at any position of its peptide bond with a second starting material having a reactive amino group corresponding to the other fragment, subsequently eliminating protective groups of the C-terminal α-carboxyl group and the N-terminal α-amino group of the resulting compound concurrently or stepwise, thereafter conducting intramolecular condensation of both by methods known in the art to obtain a cyclic compound, and then, eliminating protective groups by methods known in the art, if the resulting condensed product has any protective groups.
The above starting materials are usually amino acid and/or peptide fragments which, taken together, form the cyclic hexapeptide of the desired formula [I] or a salt thereof. They are usually linear or branched. The reactive carboxyl group means carboxyl group itself or an activated carboxyl group. The reactive amino group means amino group itself or an activated amino group. One of the two functional groups taking part in the condensation reaction is usually activated.
The carboxyl group and the amino group which do not take part in the condensation reaction are usually protected before the condensation reaction.
Protection of functional groups which should not affect the reaction of the starting materials, the protective groups and elimination of the protective groups, and activation of functional groups related to the reaction can also be suitably selected from groups or methods known in the art.
Examples of the protective groups for the amino groups of the starting materials include benzyloxycarbonyl, t-butyloxy-carbonyl, t-amyloxycarbonyl, isobornyloxycarbonyl, 4-methoxybenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, adamantyloxycarbonyl, trifluoroacetyl, phthalyl, formyl, 2-nitrophenylsulfenyl, diphenylphosphinothioyl and 9-fluorenylmethyloxycarbonyl. The protective groups for the carboxyl groups include, for example, alkyl esters (such as esters of methyl, ethyl, propyl, butyl, t-butyl, cyclo-pentyl, cyclohexyl, cycloheptyl, cyclooctyl and 2-adamantyl), benzyl esters, 4-nitrobenzyl esters, 4-methoxybenzyl esters, 4-chlorobenzyl esters, benzhydryl esters, phenacyl esters, benzyloxycarbonylhydrazide, t-butyloxycarbonylhydrazide and tritylhydrazide.
The hydroxyl group of serine can be protected, for example, by esterification or etherification. Examples of groups suitable for this esterification include lower aliphatic acyl groups such as acetyl, arylacyl groups such as benzoyl, and carbonic acid-derived groups such as benzyloxycarbonyl and ethyloxycarbonyl. Examples of groups suitable for the etherification include benzyl, tetrahydropyranyl and t-butyl. However, the hydroxyl group of serine is not always required to be protected.
Examples of the protective groups for the phenolic hydroxyl group of tyrosine include benzyl, 2,6-dichlorobenzyl, 2-nitrobenzyl, 2-bromobenzyloxycarbonyl and t-butyl. However, the phenolic hydroxyl group of tyrosine is not always required to be protected.
Methionine may be protected in the form of sulfoxides.
The protective groups for the imidazole ring of histidine include p-toluenesulfonyl, 4-methoxy-2,3,6-trimethylbenzenesulfonyl, 2,4-dinitrophenyl, benzyloxymethyl, t-butoxymethyl, t-butoxycarbonyl, trityl and 9-fluorenylmethyloxycarbonyl. However, the imidazole ring is not always required to be protected.
The protective groups for the indole ring of tryptophan include formyl, 2,4,6-trimethylbenzensulfonyl, 2,4,6-trimethoxybenzenesulfonyl, 4-methoxy-2,3,6-trimethylbenzenesulfonyl, 2,2,2-trichloroethyloxycarbonyl and diphenylphosphinothioyl. However, the indole ring is not always required to be protected.
Examples of the activated carboxyl groups of the starting materials include the corresponding acid anhydrides, azides and active esters (esters of alcohols such as pentachloro-phenol, 2,4,5-trichlorophenol, 2,4-dinitrophenol, cyano-methyl alcohol, p-nitrophenol, N-hydroxy-5-norbornene-2,3-dicarboxyimide, N-hydroxysuccinimide, N-hydroxyphthalimide and N-hydroxybenzotriazole. Examples of the activated amino acid groups of the raw materials include the corresponding phosphoric acid amides.
Condensation reaction can be conducted in the presence of a solvent(s). The solvent(s) can be appropriately selected from the solvents commonly used in peptide condensation reactions. Examples of the solvents include anhydrous or hydrous dimethylformamide, dimethyl sulfoxide, pyridine, chloroform, dioxane, dichloromethane, tetrahydrofuran, acetonitrile, ethyl acetate, N-methylpyrrolidone and appropriate mixtures thereof.
The reaction temperature is appropriately selected from the temperature range commonly used in peptide bond-forming reactions, usually from the range of about -20° to about 30° C.
Intramolecular cyclization reaction can be conducted at any position of the peptide by methods known in the art. For example, the protective group of the C-terminal α-carboxyl group of the protected peptide is first eliminated by methods known in the art, and then, the carboxyl group is activated by methods known in the art, followed by elimination of the protective group of the N-terminal α-amino group by methods known in the art and intramolecular cyclization. The protective groups of the C-terminal α-carboxyl group and the N-terminal α-amino group of the protected peptide may be concurrently eliminated, followed by intramolecular cyclization according to known condensation reaction. In some cases, intramolecular cyclization reaction is preferably conducted in a highly diluted state.
Examples of methods for eliminating the protective groups include catalytic reduction in the presence of a catalyst such as palladium black or Pd-carbon in a stream of hydrogen, acid treatment with anhydrous hydrogen fluoride, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid or mixtures thereof, and reduction with sodium in liquid ammonia. The elimination reaction by the above-mentioned acid treatment is generally conducted at a temperature between -20° and 40° C. In the acid treatment, it is effective to add a cation trapping agent such as anisole, phenol, thioanisole, m-cresol, p-cresol, dimethylsulfide, 1,4-butanedithiol or 1,2-ethanedithiol. The 2,4-dinitrophenyl group used as the protective group for the imidazole ring of histidine is eliminated by thiophenol treatment. The formyl group used as the protective group for the indole ring of tryptophan may be eliminated by either (i) alkali treatment using dilute sodium hydroxide, dilute ammonia or the like, or (ii) the above-mentioned elimination by the acid treatment in the presence of 1,2-ethanedithiol, 1,4-butanedithiol or the like.
After completion of the reaction, the cyclic peptide [I] thus obtained is collected by conventional separation and purification methods of peptides such as extraction, distribution, reprecipitation, recrystallization, column chromatography and high performance liquid chromatography.
The cyclic peptides [I] of the present invention can be obtained by methods known in the art as the metal salts, the salts of bases or basic compounds, the inorganic acid addition salts, the organic acid salts and the like, and particularly as pharmaceutically acceptable acid addition salts such as the salts of inorganic acids (for example, hydrochloric acid, sulfuric acid and phosphoric acid) or organic acids (for example, acetic acid, propionic acid, citric acid, tartaric acid, malic acid, oxalic acid and methanesulfonic acid).
In this specification, amino acids and peptides are indicated by the abbreviations commonly used in the art or adopted by the IUPAC-IUB Commission on Biochemical Nomenclature. For example, the following abbreviations are used:
______________________________________                                    
Gly           Glycine                                                     
Sar           Sarcosine (N-methylglycine)                                 
Ala           Alanine                                                     
Val           Valine                                                      
Nva           Norvaline                                                   
Ile           Isoleucine                                                  
aIle          Alloisoleucine                                              
Nle           Norleucine                                                  
Leu           Leucine                                                     
N-MeLeu       N-Methylleucine                                             
tLeu          t-Leucine                                                   
γMeLeu  γ-Methylleucine                                       
Met           Methionine                                                  
Arg           Arginine                                                    
Arg(Tos)      N.sup.g -p-Toluenesulfonylarginine                          
Lys           Lysine                                                      
Lys(Mtr)      N(ε)-(4-Methoxy-2,3,6-trimethyl-                    
              benzenesulfonyl)lysine                                      
Orn           Ornithine                                                   
Orn(COPh)     N(δ)-Benzoylornithine                                 
Orn(COCH.sub.2 Ph)                                                        
              N(δ)-Phenylacetylornitine                             
Orn(COCH.sub.2 CH.sub.2 Ph)                                               
              N(δ)-(3-Phenylpropionyl)ornithine                     
Orn(COCH.sub.2 --Ind)                                                     
              N(δ)-({Indole-3-yl}acetyl)ornithine                   
His           Histidine                                                   
His(Bom)      N(π)-Benzyloxymethylhistidine                            
His(Bzl)      N(τ)-Benzylhistidine                                    
Asp           Aspartic acid                                               
Asn(CH.sub.2 Ph)                                                          
              N.sup.4 -Benzylasparagine                                   
Asn(CH.sub.2 CH.sub.2 Ph)                                                 
              N.sup.4 -Phenethylasparagine                                
Asn(CH.sub.2 CH.sub.2 --Ind)                                              
              N.sup.4 -(2-{Indole-3-yl}ethyl)asparagine                   
Asn(Me.CH.sub.2 CH.sub.2 Ph)                                              
              N.sup.4 -Methyl-N.sup.4 -phenethylasparagine                
Asn(CH.sub.2 CHMePh)                                                      
              N.sup.4 -({2-phenyl}propyl)asparagine                       
Asp(R1)       Aspartic acid β-4-phenylpiperazine-                    
              amide                                                       
Asp(R2)       Aspartic acid β-4-phenylpiperidine-                    
              amide                                                       
Asp(R3)       Aspartic acid β-indolineamide                          
Asp(R4)       Aspartic acid β-1-aminoindanamide                      
Asp(R5)       Aspartic acid β-1-aminotetrahydro-                     
              naphthaleneamide                                            
Asp(R6)       Aspartic acid β-4-acetylpiperazine-                    
              amide                                                       
Glu           Glutamic acid                                               
Gln(CH.sub.2 Ph)                                                          
              N.sup.5 -Benzylglutamine                                    
Gln(CH.sub.2 CH.sub.2 Ph)                                                 
              N.sup.5 -Phenethylglutamine                                 
Gln(CH.sub.2 CH.sub.2 --Ind)                                              
              N.sup.5 -(2-{Indole-3-yl}ethyl)glutamine                    
Glu(R3)       Glutamic acid γ-indolineamide                         
Glu(R4)       Glutamic acid γ-1-aminoindanamide                     
Glu(R5)       Glutamic acid γ-1-aminotetrahydro-                    
              naphthaleneamide                                            
Cys           Cysteine                                                    
Cta           Cysteic acid                                                
Ser           Serine                                                      
Ser(Bzl)      O-Benzylserine                                              
Thr           Threonine                                                   
Thr(Bzl)      O-Benzylthreonine                                           
Pro           Proline                                                     
Tpr           Thioproline                                                 
Hys           4-Hydroxyproline                                            
Hys(Bzl)      4-Benzyloxyproline                                          
Azc           Azetidine-2-carboxylic acid                                 
Pip           Pipecolic acid (piperidine-2-                               
              carboxylic acid)                                            
Phe           Phenylalanine                                               
N-MePhe       N-Methylphenylalanine                                       
Tyr           Tyrosine                                                    
Trp           Tryptophan                                                  
mTrp          5-Methyltryptophan                                          
N-MeTrp       N(α)-Methyltryptophan                                 
Trp(Me)       N.sup.in -Methyltryptophan                                  
Trp(For)      N.sup.in -Formyltryptophan                                  
Trp(Ac)       N.sup.in -Acethyltryptophan                                 
Phg           Phenylglycine                                               
Nal(1)        1-Naphthylalanine                                           
Nal(2)        2-Naphthylalanine                                           
Thi           2-Thienylalanine                                            
Thg(2)        2-Thienylglycine                                            
Thg(3)        3-Thienylglycine                                            
Acpr          1-Aminocyclopropane-1-carboxylic acid                       
Acbu          1-Aminocyclobutane-1-carboxylic acid                        
Acpe          1-Aminocyclopentane-1-carboxylic acid                       
Achx          1-Aminocyclohexane-1-carboxylic acid                        
Achp          1-Aminocycloheptane-1-carboxylic acid                       
Tic           Tetrahydroisoquinoline-2-carboxylic                         
              acid                                                        
______________________________________                                    

______________________________________                                    
AcOEt    Ethyl acetate                                                    
Boc      t-Butoxycarbonyl                                                 
Bzl      Benzyl                                                           
BrZ      2-Bromobenzyloxycarbonyl                                         
Clz      2-Chlorobenzyloxycarbonyl                                        
Tos      p-Toluenesulfonyl                                                
For      Formyl                                                           
OBzl     Benzyl ester                                                     
0Pac     Phenacyl ester                                                   
ONB      HONB ester                                                       
TFA      Trifluoroacetic acid                                             
TEA      Triethylamine                                                    
IBCF     Isobutyl chloroformate                                           
DMF      N,N-Dimethylformamide                                            
DCC      N,N'-Dicyclohexylcarbodiimide                                    
DCU      N,N'-Dicyclohexylurea                                            
HONB     N-Hydroxy-5-norbornene-2,3-dicarboxy-imide                       
HOBt     1-Hydroxybenzotriazole                                           
DCM      Dichloromethane                                                  
THF      Tetrahydrofuran                                                  
______________________________________
The cyclic peptides of the present invention have the following pharmacological activity. Namely, the novel cyclic peptides [I] of the present invention or the pharmaceutically acceptable salts thereof have the antagonistic activity on endothelin receptors as shown in the experimental examples described below. Further, the certain group of cyclic peptides [I] or pharmaceutically acceptable salt thereof also have the antagonistic activity on NK2 receptors. The cyclic peptides [I] or pharmaceutically acceptable salt thereof can be used as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases, renal diseases, asthma and the like, because they have the antagonistic activity on endothelin receptors. Further, the cyclic peptides [I] or pharmaceutically acceptable salt thereof having the antagonistic activity on NK2 receptors in addition can also be used as anti-inflammatory drugs and antarthritics.
Recent investigations on the endothelin receptors revealed that the endothelin receptors have two subtypes (ETA and ETB) [for example, the Twelfth Medicinal Chemistry Symposium-the First Annual Meeting of the Medical Chemistry Section, Okayama, Dec. 4 to 6, 1991, Summaries of Lectures, page 82 (Lecture No. P-20); the Third Endothelin Symposium, Tsukuba, Dec. 13 and 14, 1991, Summaries of Lectures, (Lecture No. P-05); and Nature, 348, 730-735 (1990)]. Preferred novel cyclic peptides [I] of the present invention strongly bind not only to ETA, but also to ETB to act as the antagonists on endothelin receptors, as shown in the experimental examples described below. Further, the certain group of the novel cyclic peptides [I] of the present invention have the antagonistic activity on NK2 receptors, one of tachykinin peptide receptors, in addition. As the tachykinin family, substance P, neurokinin A and neurokinin B are known [Y. Yokoto et al., J. Biol. Chem., 264, 17649 (1989); A. D. Hershey et al., Science, 247, 958 (1990); Y. Sasai et al., Biochem. Biophys. Res. Commun., 165, 695 (1989); R. Shigemoto et al., J. Biol. Chem., 265, 623 (1990); and A. Graham et al., Biochem. Biophys. Res. Commun., 177, 8 (1991)], and NK1, NK2 and NK3 are known respectively, as receptors corresponding to ligands thereof. Antagonists on NK receptors are described in Japanese Patent Unexamined Publication Nos. 2197/1991, 17098/1991 and 141295/1991. However, the compounds disclosed therein are different from the cyclic hexapeptides [I] of the present invention in structure.
The novel cyclic peptides [I] of the present invention have the remarkable effect of suppressing the vasopressor activity of endothelin as the antagonists on endothelin receptors, and some of them also have the strong activity as the antagonists on NK2 receptors. For this reason, the novel cyclic peptides of the present invention or the salts thereof can be used as prophylactic and therapeutic drugs for hypertension, cardiac or cerebral circulatory diseases (for example, cardiac infarction), renal diseases for example, acute renal insufficiency), asthma and the like. Further, the cyclic peptides having the antagonistic activity on NK2 receptors in addition can also be used as the anti-inflammatory drugs and the antarthritics.
The cyclic peptides of the present invention, when used as the above-mentioned prophylactic and therapeutic drugs, can be safely administered orally or parenterally in the form of powders, granules, tablets, capsules, injections, suppositories, ointments or sustained release preparations, alone or in combination with pharmaceutically acceptable carriers, excipients or diluents. The peptides of the present invention are typically administered parenterally, for example, by intravenous or subcutaneous injection, intraventricular or intraspinal administration, nasotracheal administration or intrarectal administration. In some cases, however, they are administered orally.
The cyclic peptides of the present invention are generally stable substances, and therefore, can be stored as physiological saline solutions. It is also possible to lyophilize the peptides, store them in ampules with mannitol or sorbitol, and dissolve them in a suitable carrier at the time of use. The cyclic peptides of the present invention can be given in their free forms, or in the form of base salts or acid addition salts thereof. All of the free cyclic peptides, the base salts and the acid addition salts thereof are generally given in a proper dose within the range of 1 μg to 100 mg of free peptide per kg of weight. More specifically, although the dosage varies depending on the type of disease to be treated, the symptom of the disease, the object to which the drugs are given and the route of administration, when given by injection to adult patients of hypertension, for example, it is advantageous that the active ingredients (the peptides [I] or pharmaceutically acceptable salt thereof) are normally given in one dose of about 1 μg to 100 mg/kg of weight, more preferably about 100 μg to 20 mg/kg of weight, most preferably 1 mg to 20 mg/kg of weight, about once to 3 times a day. In injection, the peptides [I] are usually given intravenously. Drip infusion is also effective. In this case, the total dosage is the same as with injection.
When the cyclic peptides of the present invention or the pharmaceutically acceptable salts thereof are used as the prophylactic or therapeutic drugs, they must be carefully purified so as to contain no bacteria and no pyrogens.
The present invention will be described in more detail with the following examples and experimental examples, in which all amino acid residues take the L-form unless otherwise specified, when they have the D- and L-forms.
In the following examples, SILICAGEL 60F-254 (Merck) was used as the plates of thin layer chromatography, and chloroform-methanol (19:1) and chloroform-methanol-acetic acid (9:1:0.5) were used as the developing solvents for Rf1 and Rf2, respectively.
EXAMPLE 1
Production of cyclo[-D-Asp-Ala-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-D-Leu-Leu-OBzl
H-Leu-OBzl.pTos (21.6 g) was dissolved in DMF (100 ml), and the solution was cooled with ice. TEA (7.7 ml) and Boc-D-Leu-ONB [prepared from Boc-D-Leu-OH.H2 O (12.5 g), HONB (9.86 g) and DCC (11.4 g) were added thereto, followed by stirring overnight. The resulting DCU was separated by filtration, and the filtrate was concentrated to obtain a residue. The residue was dissolved in AcOEt, and the resulting solution was washed with 4% aqueous NaHCO3 and 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 19.8 g (91.3%), Melting point: 94°-95° C., Rf2 : 0.76 [α]D 25 +3.6° (c=1.06, in DMF)
Elemental analysis: As C24 H38 N2 O5 Calculated: C, 66.33; H, 8.81; N, 6.45 Found: C, 66.38; H, 8.87; N, 6.53
(2) Production of Boc-D-Leu-Leu-OPac
Boc-D-Leu-Leu-OBzl (6.0 g) was dissolved in methanol (20 ml) and catalytically reduced in a stream of hydrogen using 10% Pd-carbon as a catalyst. After the catalyst was separated by filtration, the solution was concentrated to obtain a residue. The residue and Cs2 CO3 (2.1 g) were dissolved in 90% aqueous methanol, and the solution was concentrated. The resulting residue was dissolved in DMF (60 ml), and phenacyl bromide (2.8 g) was added thereto, followed by stirring overnight. The resulting TEA hydrochloride was separated by filtration, and the filtrate was concentrated to obtain a residue. The residue was dissolved in AcOEt, and the resulting solution was washed with 4% aqueous NaHCO3 and 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 5.48 g (85.8%), Melting point: 98°-99° C., Rf2 : 0.66 [α]D 25 -3.9° (c=1.09, in DMF)
Elemental analysis: As C25 H38 N2 O6 Calculated: C, 64.91; H, 8.28; N, 6.06 Found: C, 65.21; H, 8.54; N, 6.24
(3) Production of Boc-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (1.85 g) to dissolve it, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4, concentrated and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-Asp(OBzl)-ONB [prepared from Boc-Asp(OBzl)-OH (1.42 g), HONB (0.86 g) and DCC (0.99 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.31 g (86.5%), Melting point: 119°-121° C., Rf1 : 0.57, Rf2 : 0.79 [α]D 28 -40.8° (c=0.93, in DMF)
Elemental analysis: As C36 H49 N3 O9 Calculated: C, 64.75; H, 7.40; N, 6.29 Found: C, 64.73; H, 7.41; N, 6.45
(4) Production of Boc-Ala-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Ala-ONB [prepared from Boc-Ala-OH (0.61 g), HONB (0.63 g) and DCC (0.73 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2 28 g (96 4%), Melting point: 132°-133° C., Rf1 : 0.34, Rf2 : 0.66 [α]D 28 -46.6° (c=0.76, in DMF)
Elemental analysis: As C39 H54 N4 O10 Calculated: C, 63.40; H, 7.37; N, 7.58 Found: C, 63.15; H, 7.44; N, 7.66
(5) Production of Boc-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.77 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.08 g (91.8%), Melting point: 92°-94° C., Rf1 : 0.38, Rf2 : 0.70 [α]D 28 -21.0° (c=0.64, in DMF)
Elemental analysis: As C50 H65 N5 O13 Calculated: C, 63.61; H, 6.94; N, 7.42 Found: C, 63.33; H, 6.98; N, 7.52
(6) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.60 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml), and cooled with ice. Then, TEA (0.48 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.61 g (83.8%), Melting point: 160°-162° C., Rf1 : 0.35, Rf2 : 0.68 [α]D 28 +17.5° (c=0.71, in DMF)
Elemental analysis: As C61 H75 N7 O14 Calculated: C, 64.82; H, 6.69; N, 8.67 Found: C, 64.70; H, 6.72; N, 8.81
(7) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(BOzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OPac (1.47 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.23 g (93.5%), Melting point: 195°-196° C., Rf1 : 0.14, Rf2 : 0.67 [α]D 28 +27.1° (c=0.65, in DMF)
Elemental analysis: As C53 H69 N7 O13 Calculated: C, 62.89; H, 6.87; N, 9.69 Found: C, 63.02; H, 6.57; N, 9.68
(8) Production of cyclo[-D-Asp-Ala-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Ala-Asp(OBzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8-N HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 89 mg was dissolved in DMF (15 ml), and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 13.6 mg (18.2%).
Anal. for amino acids [6-N HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Ala 1.06(1); Leu 2.11(2) LSIMS (M+H+)=714, (theoretical value)=714
EXAMPLE 2
Production of cyclo[-D-Asp-Ala-D-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-D-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (1.85 g) prepared in EXAMPLE 1 (2) to dissolve it, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4 and concentrated. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.42 g), HONB (0.86 g) and DCC (0.99 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.58 g (96.4%), Melting point: 113°-114° C., Rf1 : 0.51, Rf2 : 0.75 [α]D 28 +14.2° (c=1.23, in DMF)
Elemental analysis: As C36 H49 N3 O9 Calculated: C, 64.75; H, 7.40; N, 6.29 Found: C, 64.78; H, 7.50; N, 6.47
(2) Production of Boc-Ala-D-Asp(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Ala-ONB [prepared from Boc-Ala-OH (0.61 g), HONB (0.63 g) and DCC (0.73 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.08 g (88.0%), Melting point: 167°-168° C., Rf1 : 0.36, Rf2 : 0.67 [α]D 28 +5.99° (c=0.94, in DMF)
Elemental analysis: As C39 H54 N4 O10 Calculated: C, 63.40; H, 7.37; N, 7.58 Found: C, 63.32; H, 7.47; N, 7.74
(3) Production of Boc-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-D-Asp(OBzl)-D-Leu-Leu-OPac (1.77 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.79 g (79 0%), Melting point: 120°-121° C., Rf1 : 0.37, Rf2 : 0.70 [α]D 28 +34.2° (c=0.85, in DMF)
Elemental analysis: As C50 H65 N5 O13 Calculated: C, 63.61; H, 6.94; N, 7.42 Found: C, 63.70; H, 6.89; N, 7.63
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-D-Asp(OBzl)-D-Leu-Leu-OPac (1.60 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1 62 g (84 3%), Melting point: 178°-179° C., Rf1 : 0.37, Rf2 : 0.69 [α]D 28 +41.1° (c=0.84, in DMF)
Elemental analysis: As C61 H75 N7 O14 Calculated: C, 64.82; H, 6.69; N, 8.67 Found: C, 64.69; H, 6.74; N, 8.88
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OPac (1.47 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.23 g (93.5%), Melting point: 165°-166° C., Rf1 : 0.17, Rf2 : 0.67 [α]D 28 +54.5° (c=1.05, in DMF)
Elemental analysis: As C53 H69 N7 O13 Calculated: C, 62.89; H, 6.87; N, 9.69 Found: C, 62.59; H, 7.05; N, 9.63
(6) Production of cyclo[-D-Asp-Ala-D-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Ala-D-Asp(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 89 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 23.4 mg (15.3%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Ala 1.04(1); Leu 2.07(2) LSIMS (M+H+)=714, (theoretical value)=714
EXAMPLE 3
Production of cyclo[-D-Asp-Ala-Glu-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Glu(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (1.85 g) prepared in example 1 (2) to dissolve it, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4 and concentrated. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-Glu(OBzl)-ONB [prepared from Boc-Glu(OBzl)-OH (1.48 g), HONB (0.86 g) and DCC (0.99 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.04 g (74.5%), Melting point: 118°-120° C., Rf1 : 0.41, Rf2 : 0.71 [α]D 28 -23.8° (c=0.84, in DMF)
Elemental analysis: As C37 H51 N3 O9 Calculated: C, 65.18; H, 7.54; N, 6.16 Found: C, 65.20; H, 7.73; N, 6.34
(2) Production of Boc-Ala-Glu(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Glu(OBzl)-D-Leu-Leu-OPac (1.91 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.88 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Ala-ONB [prepared from Boc-Ala-OH (0.53 g), HONB (0.55 g) and DCC (0.64 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in ACOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.00 g (94.9%), Melting point: 129°-130° C., Rf1 : 0.36, Rf2 : 0.67 [α]D 28 -32.9° (c=1.03, in DMF)
Elemental analysis: As C40 H56 N4 O10 Calculated: C, 63.81; H, 7.50; N, 7.44 Found: C, 63.70; H, 7.55; N, 7.62
(3) Production of Boc-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-Glu(OBzl)-D-Leu-Leu-OPac (1.81 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2 07 g (90 0%), Melting point: 149°-151° C., Rf1 : 0.34, Rf2 : 0.69 [α]D 28 +3.00° (c=1.14, in DMF)
Elemental analysis: As C51 H67 N5 O13 Calculated: C, 63.93; H, 7.05; N, 7.31 Found: C, 64.01; H, 7.11; N, 7.48
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-Glu(OBzl)-D-Leu-Leu-OPac (1.63 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1 91 g (98 2%), Melting point: 172°-174° C., Rf1 : 0.37, Rf2 : 0.69 [α]D 28 +28.8° (c=0.68, in DMF)
Elemental analysis: As C62 H77 N7 O14 Calculated: C, 65.08; H, 6.78; N, 8.57 Found: C, 64.84; H, 6.83; N, 8.80
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.30 g (97.5%), Melting point: 192°-194° C., Rf1 : 0.12, Rf2 : 0.66 [α]D 28 +37.7° (c=0.92, in DMF)
Elemental analysis: As C54 H71 N7 O13 Calculated: C, 63.20; H, 6.97; N, 9.55 Found: C, 63.02; H, 6.96; N, 9.63
(6) Production of cyclo[-D-Asp-Ala-Glu-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Ala-Glu(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 91 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 17.7 mg (24.1%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 1.00(1); Glu 1.04(1); Ala 1.05 (1); Leu 2.07(2) LSIMS (M+H+)=728, (theoretical value)=728
EXAMPLE 4
Production of cyclo[-D-Asp-Ala-D-Glu-D-Leu-Leu-D-Trp-]
(1) Production of Boc-D-Glu(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (1.85 g) prepared in example 1 (2) to dissolve it, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4 and concentrated. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Glu(OBzl)-ONB [prepared from Boc-D-Glu(OBzl)-OH (1.48 g), HONB (0.86 g) and DCC (0.99 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.21 g (81.0%), Melting point: 136°-137° C., Rf1 : 0.40, Rf2 : 0.68 [α]D 28 -3.33° (c=1.02, in DMF)
Elemental analysis: As C37 H51 N3 O9 Calculated: C, 65.18; H, 7.54; N, 6.16 Found: C, 65.23; H, 7.65; N, 6.10
(2) Production of Boc-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Glu(OBzl)-D-Leu-Leu-OPac (1.91 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.88 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Ala-ONB [prepared from Boc-Ala-OH (0.53 g), HONB (0.55 g) and DCC (0.64 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.92 g (91.1%), Melting point: 187°-188° C., Rf1 : 0.36, Rf2 : 0.68 [α]D 28 -15.2° (c=0.94, in DMF)
Elemental analysis: As C40 H56 N4 O10 Calculated: C, 63.81; H, 7.50; N, 7.44 Found: C, 63.91; H, 7.59; N, 7.74
(3) Production of Boc-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac (1.81 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.75 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.85 g), HONB (0.51 g) and DCC (0.60 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.83 g (79.6%), Melting point: 116°-117° C., Rf1 : 0.35, Rf2 : 0.69 [α]D 28 +17.40 (c=0.80, in DMF)
Elemental analysis: As C51 H67 N5 O13 Calculated: C, 63.93; H, 7.05; N, 7.31 Found: C, 63.77; H, 7.01; N, 7.44
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Ala-D-Glu(OBzl)-D-Leu-Leu-OPac (1.63 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (0.53 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.48 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.57 g), HONB (0.37 g) and DCC (0.42 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.64 g (84.3%), Melting point: 149°-150° C., Rf1 : 0.38, Rf2 : 0.70 [α]D 28 +24.2° (c=0.66, in DMF)
Elemental analysis: As C62 H77 N7 O14 Calculated: C, 65.08; H, 6.78; N, 8.57 Found: C, 64.91; H, 6.86; N, 8.67
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (4.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.24 g (93.0%), Melting point: 147°-149° C., Rf1 : 0.18, Rf2 : 0.67 [α]D 28 +44.1° (c=0.86, in DMF)
Elemental analysis: As C54 H71 N7 O13 Calculated: C, 63.20; H, 6.97; N, 9.55 Found: C, 62.90; H, 7.10; N, 9.48
(6) Production of cyclo[-D-Asp-Ala-D-Glu-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Ala-D-Glu(BOzl)-D-Leu-Leu-OH (0.51 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8-N HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 91 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 14.3 mg (10.8%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 1.00(1); Glu 1.04(1); Ala 1.05(1); Leu 2.09(2) LSIMS (M+H+)=728, (theoretical value)=728
EXAMPLE 5
Production of cyclo[-D-Asp-Gly-Ala-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Leu-Leu-OPac (6.50 g) prepared in example 1 (2) to dissolve it, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4 and concentrated. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (2.07 ml) was added thereto. Boc-Ala-ONB [prepared from Boc-Ala-OH (2.67 g), HONB (2.65 g) and DCC (3.05 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 6 70 g (90 0%), Melting point: 121.0°-122.0° C., Rf1 : 0.56, Rf2 : 0.71 [α]D 25 -12.0° (c=1.01, in DMF)
Elemental analysis: As C28 H43 N3 O7 Calculated: C, 63.02; H, 8.12; N, 7.87 Found: C, 63.07; H, 7.90; N, 7.92
(2) Production of Boc-Gly-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-D-Leu-Leu-OPac (2.20 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.61 ml) was added thereto. Boc-Gly-ONB [prepared from Boc-Gly-OH (0.72 g), HONB (0.78 g) and DCC (0.89 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2 26 g (93 2%), Melting point: 158.5°-160.0° C., Rf1 : 0.30, Rf2 : 0.54 [α]D 25 -4.8° (c=1.02, in DMF)
Elemental analysis: As C30 H46 N4 O8 Calculated: C, 61.00; H, 7.85; N, 9.48 Found: C, 60.92; H, 7.91; N, 9.66
(3) Production of Boc-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Gly-Ala-D-Leu-Leu-OPac (2.23 g) to dissolve it, followed by concentration. 8-N HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.55 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.22 g), HONB (0.71 g) and DCC (0.82 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.62 g (87.3%), Melting point: 68.0°-69.5° C., Rf1 : 0.25, Rf2 : 0.53 [α]D 25 +5.4° (c=1.03, in DMF)
Elemental analysis: As C41 H57 N5 O11 Calculated: C, 61.87; H, 7.22; N, 8.80 Found: C, 61.78; H, 7.34; N, 8.62
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac (2.51 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.96 g), HONB (0.59 g) and DCC (0.68 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.52 g (49.1%), Melting point: 109.5°-110.0° C., Rf1 : 0.27, Rf2 : 0.54 [α]D 25 +9.0° (c=1.04, in DMF)
Elemental analysis: As C52 H67 N7 O12 Calculated: C, 63.59; H, 6.88; N, 9.98 Found: C, 63.72; H, 6.96; N, 10.17
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Gly-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 385 mg (87 5%), Melting point: 120.0°-122.0° C., Rf1 : 0.02, Rf2 : 0.40 [α]D 25 +23.0° (c=1.01, in DMF)
Elemental analysis: As C44 H61 N7 O11 Calculated: C, 61.17; H, 7.12; N, 11.35 Found: C, 61.28; H, 7.08; N, 11.11
(6) Production of cyclo[-D-Asp-Gly-Ala-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D/Asp(OBzl)-Gly-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 51 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 28.5 mg (19.2%).
Anal. for amino acids [6-N HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 1.00(1); Gly 1.03(1); Ala 1.04(1); Leu 2.09(2) LSIMS (M+H+)=656, (theoretical value)=656
EXAMPLE 6
Production of cyclo[-D-Asp-Asp-Ala-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Asp(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-D-Leu-Leu-OPac (2.20 g) prepared in example 5 (1) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.61 ml) was added thereto. Boc-Asp(OBzl)-ONB [prepared from Boc-Asp(OBzl)-OH (1.33 g), HONB (0.78 g) and DCC (0.89 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.87 g (94.2%), Melting point: 149.5°-150.5° C., Rf1 : 0.58, Rf2 : 0.68 [α]D 25 -15.2° (c=1.02, in DMF)
Elemental analysis: As C39 H54 N4 O10 Calculated: C, 63.40; H, 7.37; N, 7.58 Found: C, 63.55; H, 7.42; N, 7.68
(2) Production of Boc-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Asp(OBzl)-Ala-D-Leu-Leu-OPac (2.77 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.55 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.21 g), HONB (0.71 g) and DCC (0.81 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 3.08 g (87.0%), Melting point: 72.0°-74.0° C., Rf1 : 0.56, Rf2 : 0.64 [α]D 25 -7.0° (c=1.02, in DMF)
Elemental analysis: As C50 H65 N5 O13 Calculated: C, 63.61; H, 6.94; N, 7.42 Found: C, 63.38; H, 6.88; N, 7.42
(3) Production of Boc-D-Trp-D-Asp(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OPac (2.94 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.96 g), HONB (0.59 g) and DCC (0.68 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.61 g (77.0%), Melting point: 190.0°-192.5° C., Rf1 : 0.49, Rf2 : 0.60 [α]D 25 +4.9° (c=1.03, in DMF)
Elemental analysis: As C61 H75 N7 O14 Calculated: C, 64.82; H, 6.69; N, 8.67 Found: C, 65.01; H, 6.78; N, 8.87
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 363 mg (81.0%), Melting point: 174.0°-175.0° C., Rf1 : 0.04, Rf2 : 0.50 [α]D 25 +12.1° (c=1.03, in DMF)
Elemental analysis: As C53 H69 N7 O13 Calculated: C, 62.89; H, 6.87; N, 9.69 Found: C, 62.92; H, 6.89; N, 9.78
(5) Production of cyclo[-D-Asp-Asp-Ala-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Asp(OBzl)-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice. HONB (0.16 g) and DCC (0.18 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.62 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 51 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 28.5 mg (17.8%).
Anal for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Ala 1.04(1); Leu 2.10(2) LSIMS (M+H+)=714, (theoretical value)=714
EXAMPLE 7
Production of cyclo[-D-Asp-Glu-Ala-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Glu(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Ala-D-Leu-Leu-OPac (2.20 g) prepared in example 5 (1) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.61 ml) was added thereto. Boc-Glu(OBzl)-ONB [prepared from Boc-Glu(OBzl)-OH (1.39 g), HONB (0.78 g) and DCC (0.89 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.86 g (92.4%), Melting point: 152.5°-153.5° C., Rf1 : 0.36, Rf2 : 0.67 [α]D 25 +0.8° (c=1.04, in DMF)
Elemental analysis: As C40 H56 N4 O10 Calculated: C, 63.81; H, 7.50; N, 7.44 Found: C, 63.86; H, 7.53; N, 7.65
(2) Production of Boc-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-Glu(OBzl)-Ala-D-Leu-Leu-OPac (2.76 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.54 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (1.19 g), HONB (0.69 g) and DCC (0.80 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 3.08 g (87.6%), Melting point: 127.0°-127.5° C., Rf1 : 0.51, Rf2 : 0.60 [α]D 25 +4.5° (c=1.01, in DMF)
Elemental analysis: As C51 H67 N5 O13 Calculated: C, 63.93; H, 7.05; N, 7.31 Found: C, 64.05; H, 7.08; N, 7.42
(3) Production of Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac
TFA (20 ml) was added to Boc-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac (2.95 g) to dissolve it, followed by concentration. 8N-HCl/dioxane (1.00 ml) was added thereto, and ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.46 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.94 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.59 g (75.4%), Melting point: 182.0°-183.5° C., Rf1 : 0.51, Rf2 : 0.62 [α]D 25 +12.1° (c=1.03, in DMF)
Elemental analysis: As C62 H77 N7 O14 Calculated: C, 65.08; H, 6.78; N, 8.57 Found: C, 65.11; H, 6.76; N, 8.76
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OPac (0.50 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.66 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 410 mg (91.4%), Melting point: 179.5°-180.5° C., Rf1 : 0.03, Rf2 : 0.53 [α]D 25 +16.1° (c=1.02, in DMF)
Elemental analysis: As C54 H71 N7 O13 Calculated: C, 63.20; H, 6.97; N, 9.55 Found: C, 63.45; H, 7.00; N, 9.67
(5) Production of cyclo[-D-Asp-Glu-Ala-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Glu(OBzl)-Ala-D-Leu-Leu-OH (0.51 g) was dissolved in acetonitrile (20 ml), and the solution was cooled with ice. HONB (0.16 g) and DCC (0.18 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. Ethanedithiol (0.09 ml) and 8N-HCl/dioxane (20 ml) were added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.62 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 51 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 28.5 mg (20.6%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 1.00(1); Glu 1.02(1); Ala 1.05(1); Leu 2.06(2) LSIMS (M+H+)=728, (theoretical value)=728
EXAMPLE 8
Production of cyclo[-D-Asp-Trp-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Trp-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) prepared in example 1 (3) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Trp-ONB [prepared from Boc-Trp-OH (1.17 g), HONB (0.69 g) and DCC (0.79 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.48 g (90.7%), Melting point: 143°-144° C., Rf1 : 0.43, Rf2 : 0.74 [α]D 28 -25.8° (c=0.98, in DMF)
Elemental analysis: As C47 H59 N5 O10 Calculated: C, 66.10; H, 6.96; N, 8.20 Found: C, 66.22; H, 7.01; N, 8.49
(2) Production of Boc-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Trp-Asp(OBzl)-D-Leu-Leu-OPac (2.31 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.75 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.96 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.48 g (86.7%), Melting point: 171°-172° C., Rf1 : 0.41, Rf2 : 0.72 [α]D 28 -16.0° (c=1.31, in DMF)
Elemental analysis: As C58 H70 N6 O13 Calculated: C, 65.77; H, 6.66; N, 7.93 Found: C, 65.82; H, 6.91; N, 8.10
(3) Production of Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac (2.12 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.49 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration. Yield: 2.10 g (93.1%), Melting point: 180°-181° C., Rf1 : 0.33, Rf2 : 0.69 [α]D 28 -4.4° (c=1.11, in DMF)
Elemental analysis: As C69 H80 N8 O14 Calculated: C, 66.54; H, 6.47; N, 9.00 Found: C, 66.45; H, 6.76; N, 9.10
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OPac (1.49 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (3.92 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.30 g (96.1%), Melting point: 114°-115° C., Rf1 : 0.10, Rf2 : 0.65 [α]D 28 +1.6° (c=0.87, in DMF)
Elemental analysis: As C61 H74 N8 O13 Calculated: C, 64.99; H, 6.62; N, 9.94 Found: C, 65.01; H, 6.88; N, 10.02
(5) Production of cyclo[-D-Asp-Trp-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-D-Leu-Leu-OH (0.56 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile-ether was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 101 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 12.4 mg (52.9%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.15(2) LSIMS (M+H+)=829, (theoretical value)=829
EXAMPLE 9
Production of cyclo[-D-Asp-Pro-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Pro-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.14 g) prepared in example 1 (3) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.90 ml) was added thereto. Boc-Pro-ONB [prepared from Boc-Pro-OH (0.76 g), HONB (0.69 g) and DCC (0.79 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.19 g (89.5%), Melting point: 135°-136° C., Rf1 : 0.44, Rf2 : 0.74 [α]D 28 -40.0° (c=1.02, in DMF)
Elemental analysis: As C41 H56 N4 O10 Calculated: C, 64.38; H, 7.38; N, 7.32 Found: C, 64.40; H, 7.53; N, 7.37
(2) Production of Boc-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Pro-Asp(OBzl)-D-Leu-Leu-OPac (2.07 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.75 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.96 g), HONB (0.58 g) and DCC (0.67 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.39 g (91.2%), Melting point: 59°-61° C., Rf1 : 0.48, Rf2 : 0.74 [α]D 28 -14.3° (c=1.07, in DMF)
Elemental analysis: As C52 H67 N6 O13 Calculated: C, 64.38; H, 6.96; N, 7.22 Found: C, 64.17; H, 7.18; N, 7.39
(3) Production of Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Pro-Asp(0Bzl)-D-Leu-Leu-OPac (1.94 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.49 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.82 g (78.7%), Melting point: 102°-104° C., Rf1 : 0.34, Rf2 : 0.70 [α]D 28 +8.3° (c=1.22, in DMF)
Elemental analysis: As C63 H77 N7 O14 Calculated: C, 65.44; H, 6.71; N, 8.48 Found: C, 65.32; H, 6.86; N, 8.53
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OPac (1.39 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (3.92 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.22 g (97.9%), Melting point: 110°-112° C., Rf1 : 0.13, Rf2 : 0.65 [α]D 28 +14.6° (c=1.07, in DMF)
Elemental analysis: As C55 H71 N7 O13 Calculated: C, 63.63; H, 6.89; N, 9.44 Found: C, 63.62; H, 7.17; N, 9.25
(5) Production of cyclo[-D-Asp-Pro-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Pro-Asp(OBzl)-D-Leu-Leu-OH (0.53 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.18 g) and DCC (0.21 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.7 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile-ether was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 92 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 15.2 mg (47.4%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Pro 1.03(1); Leu 2.11(2) LSIMS (M+H+)=740, (theoretical value)=740
EXAMPLE 10
Production of cyclo[-D-Asp-Asn(CH2Ph)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Asn(CH2 Ph)-OBzl
Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and benzylamine (1.09 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.90 g (92.5%), Melting point: 116.5°-117.0° C., Rf1 : 0.56, Rf2 : 0.69 [α]D 25 -11.3° (c=1.05, in DMF)
Elemental analysis: As C23 H28 N2 O5 Calculated: C, 66.97; H, 6.84; N, 6.79 Found: C, 67.25; H, 6.95; N, 7.07
(2) Production of Boc-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto. Boc-Asn(CH2 Ph)-ONB [prepared by catalytically reducing Boc-Asn(CH2 Ph)-OBzl (1.23 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washings-with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.26 g (86.7%), Melting point: 155.0°-157.0° C., Rf1 : 0.49, Rf2 : 0.70 [α]D 25 -37.1° (c=1.05, in DMF)
Elemental analysis: As C47 H61 N5 O11 Calculated: C, 64.74; H, 7.05; N, 8.03 Found: C, 64.80; H, 7.19; N, 8.25
(3) Production of Boc-D-Asp(OBzl)-Asn(CH2Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asn(CH2 ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.92 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.22 g (93.9%), Melting point: 141.5°-143.0° C., Rf1 : 0.57, Rf2 : 0.75 [α]D 25 -22.7° (c=1.01, in DMF)
Elemental analysis: As C58 H72 N6 O14 Calculated: C, 64.67; H, 6.74; N, 7.80 Found: C, 64.46; H, 6.86; N, 7.91
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.93 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.85 g (81.6%), Melting point: 149.0°-151.0° C., Rf1 : 0.47, Rf2 : 0.71 [α]D 25 -9.8° (c=1.03, in DMF)
Elemental analysis: As C69 H82 N8 O15 Calculated: C, 65.59; H, 6.54; N, 8.87 Found: C, 65.36; H, 6.70; N, 8.89
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (500 mg) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.30 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 436 mg (96.1%), Melting point: 153.0°-155.0° C., Rf1 : 0.02, Rf2 : 0.67 [α]D 25 -3.2° (c=1.02, in DMF)
Elemental analysis: As C61 H76 N8 O14 Calculated: C, 63.97; H, 6.69; N, 9.78 Found: C, 63.85; H, 6.74; N, 9.51
(6) Production of cyclo[-D-Asp-Asn(CH2 Ph)-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OH (396 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.55 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile-ether was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 50 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 19.5 mg (23.8%).
Anal for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 3.00(3); Leu 2.00(2) LSIMS (M+H+)=847, (theoretical value)=847
EXAMPLE 11
Production of cyclo[-D-Asp-Asn(CH2 CH2 Ph)-AsP-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Asn(CH2 CH2 Ph)-OBzl
Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and β-phenethylamine (0.79 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.96 g (92.3%), Melting point: 117.0°-118.5° C., Rf1 : 0.53, Rf2 : 0.68 [α]D 25 -7.3° (c=1.00, in DMF)
Elemental analysis: As C24 H30 N2 O5 Calculated: C, 67.59; H, 7.09; N, 6.57 Found: C, 67.68; H, 7.15; N, 6.75
(2) Production of Boc-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto. Boc-Asn(CH2 CH2 Ph)-ONB [prepared by catalytically reducing Boc-Asn(CH2 CH2 Ph)-OBzl (1.28 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.35 g (88.7%), Melting point: 162.0°-164.0° C., Rf1 : 0.59, Rf2 : 0.65 [α]D 25 -36.7° (c=1.03, in DMF)
Elemental analysis: As C48 H63 N5 O11 Calculated: C, 65.07; H, 7.17; N, 7.90 Found: C, 65.15; H, 7.20; N, 8.08
(3) Production of Boc-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.95 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.24 g (93.5%), Melting point: 173.0°-175.0° C., Rf1 : 0.39, Rf2 : 0.66 [α]D 25 -21.6° (c=1.02, in DMF)
Elemental analysis: As C59 H74 N6 O14 Calculated: C, 64.94; H, 6.83; N, 7.70 Found: C, 64.82; H, 6.93; N, 7.85
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (1.95 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.07 g (90.5%), Melting point: 139.5°-141.0° C., Rf1 : 0.24, Rf2 : 0.65 [α]D 25 -7.6° (c=1.00, in DMF)
Elemental analysis: As C70 H84 N8 O15 Calculated: C, 65.81; H, 6.63; N, 8.77 Found: C, 65.58; H, 6.71; N, 8.94
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OPac (500 mg) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.28 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 441 mg (97.3%), Melting point: 170.0°-172.0° C., Rf1 : 0.03, Rf2 : 0.67 [α]D 25 -1.8° (c=1.03, in DMF)
Elemental analysis: As C62 H78 N8 O14 Calculated: C, 64.23; H, 6.78; N, 9.67 Found: C, 64.08; H, 6.86; N, 9.55
(6) Production of cyclo[-D-Asp-Asn(CH2 CH2 Ph)-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-OH (401 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.55 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile-ether was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 50 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and then, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 20.5 mg (24.1%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 3.00(3); Leu 2.04(2) LSIMS (M+H+)=861, (theoretical value)=861
EXAMPLE 12
Production of cyclo[-D-Asp-Asn(CH2 CH2 -Ind)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Asn(CH2 CH2 -Ind)-OBzl
Boc-Asp-OBzl (1.61 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.98 g) and DCC (1.13 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and DMF (20 ml) containing tryptamine hydrochloride (0.98 ml) and TEA (1.04 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to obtain a desired product as a light yellow glassy material.
Yield: 1.95 g (84.1%), Rf1 : 0.42, Rf2 : 0.67 LSIMS (M+H+)=466, (theoretical value)=466
(2) Production of Boc-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.44 ml) was added thereto. Boc-Asn(CH2 CH2 -Ind)-ONB [prepared by catalytically reducing Boc-Asn(CH2 CH2 -Ind)-OBzl (1.35 g) synthesized in (1), in methanol (20 ml) in the presence of 10% Pd-carbon (20 mg) in a stream of hydrogen at ordinary temperature and pressure, separating the catalyst by filtration, followed by concentration, dissolving the residue in acetonitrile, and then adding HONB (0.56 g) and DCC (0.65 g) thereto under ice cooling] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.16 g (78.1%), Melting point: 141.0°-143.0° C., Rf1 : 0.46, Rf2 : 0.73 [α]D 25 -35.8° (c=1.06, in DMF)
Elemental analysis: As C50 H64 N6 O11 Calculated: C, 64.92; H, 6.97; N, 9.08 Found: C, 64.63; H, 7.11; N, 8.96
(3) Production of Boc-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8N-HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.32 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (0.71 g), HONB (0.41 g) and DCC (0.46 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.12 g (85.4%), Melting point: 112.5°-114.0° C., Rf1 : 0.50, Rf2 : 0.70 [α]D 25 -22.0° (c=1.02, in DMF)
Elemental analysis: As C61 H75 N7 O14 Calculated: C, 64.82; H, 6.69; N, 8.67 Found: C, 64.66; H, 6.86; N, 8.55
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac (2.00 g) was dissolved in 8-N HCl/dioxane (10 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to precipitate crystals. The crystals were separated by filtration and then dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.27 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.55 g), HONB (0.34 g) and DCC (0.39 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 2.11 g (89.5%), Melting point: 113.0°-115.0° C., Rf1 : 0.42, Rf2 : 0.68 [α]D 25 -9.2° (c=1.04, in DMF)
Elemental analysis: As C72 H85 N9 O15 Calculated: C, 65.69; H, 6.51; N, 9.58 Found: C, 65.60; H, 6.60; N, 9.49
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OPac (500 mg) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.26 g) was added thereto, followed by stirring for 3 hours. The Zn powder was separated by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 426 mg (92.5%), Melting point: 115.0°-117.5° C., Rf1 : 0.01, Rf2 : 0.65 [α]D 25 -1.4° (c=1.06, in DMF)
Elemental analysis: As C64 H79 N9 O14 Calculated: C, 64.15; H, 6.64; N, 10.52 Found: C, 64.07; H, 6.74; N, 10.38
(6) Production of cyclo[-D-Asp-Asn(CH2 CH2 -Ind)-Asp-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Leu-Leu-OH (386 mg) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.14 g) and DCC (0.16 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (90 ml) containing TEA (0.54 ml) for 30 minutes, followed by stirring overnight and concentration. Acetonitrile-ether was added to the resulting residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 40 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 19.6 mg (19.4%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 3.00(3); Leu 2.35(2) LSIMS (M+H+)=900, (theoretical value)=900
EXAMPLE 13
Production of cyclo[-D-Asp-Hyp(Bzl)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Asp(OBzl)-D-Leu-Leu-OPac (2.34 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10N-HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling. Boc-Hys(Bzl)-ONB prepared from Boc-Hyp(Bzl)-OH (1.57 g), HONB (1.16 g) and DCC (1.55 g) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO3 and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The precipitate was recrystallized from AcOEt-petroleum.
Yield: 4.01 g (92.0%), Melting point: 73.0°-74.0° C., Rf1 : 0.44, Rf2 : 0.72 [α]D 25 -33.3° (c=1.00, in DMF)
Elemental analysis: As C48 H62 N4 O11 Calculated: C, 66.19; H, 7.17; N, 6.43 Found: C, 66.19; H, 7.33; N, 6.68
(2) Production of Boc-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (3.49 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10-N HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling. Boc-D-Asp(OBzl)-ONB prepared from Boc-D-Asp(OBzl)-OH (1.55 g), HONB (1.08 g) and DCC (1.44 g) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO3 and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and the residue was purified by silica gel chromatography (Merck Kiesel Gel 60. 2% methanol/chloroform) to obtain an oily product.
Yield: 3.63 g (84.3%), Rf1 : 0.42, Rf2 : 0.74 LSIMS (M+H+)=1077, (theoretical value)=1077
(3) Production of Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac
Boc-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (3.77 g) was dissolved in dioxane (1.0 ml), and the solution was cooled with ice. 10-N HCl/dioxane (5.0 ml) was added thereto, followed by stirring for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in DMF (15 ml), and neutralized with TEA with stirring under ice cooling. Boc-D-Trp-ONB prepared from Boc-D-Trp-OH (1.17 g), HONB (752 mg) and DCC (939 mg) was added thereto and stirred overnight at room temperature. The resulting insoluble material was removed by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid, 4% aqueous NaHCO3 and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and the residue was purified by silica gel chromatography (Merck Kiesel Gel 60. 2% methanol/chloroform). Then, ether-petroleum ether was added thereto to separate out a precipitate, which was collected by filtration.
Yield: 3.44 g (91.4%), Melting point: 84.0°-85.0° C., Rf1 : 0.37, Rf2 : 0.72 [α]D 25 12.8° (c=1.00, in DMF)
Elemental analysis: As C70 H83 N7 O15 Calculated: C, 66.60; H, 6.63; N, 7.77 Found: C, 66.65; H, 6.68; N, 7.76
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OH
Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OPac (2.52 g) was dissolved in 90% aqueous AcOH (50 ml), and Zn powder (6.54 g) was added thereto with stirring under ice cooling, further followed by stirring at room temperature. The Zn powder was removed by filtration, and filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed successively with 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure.
Yield: 2.29 g (quantitative), Melting point: 94.0°-96.0° C., Rf1 : 0.17, Rf2 : 0.70 [α]D 25 19.2° (c=1.00, in DMF)
Elemental analysis: As C62 H77 N7 O14 Calculated: C, 65.07; H, 6.78; N, 8.57 Found: C, 65.05; H, 6.86; N, 8.39
(5) Production of cyclo[-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-D-Trp-]
Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-OH (1.14 g) was dissolved in dichloromethane (10 ml), and HONB (358 mg) and DCC (413 mg) were successively added thereto with stirring under ice cooling, further followed by stirring under ice cooling for 3 hours. The resulting insoluble material was removed by filtration, and the solvent was removed by distillation. The residue was dissolved in acetonitrile (20 ml), and the insoluble material was removed by filtration. The solvent was removed by distillation, and ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The resulting product was dissolved in dioxane (2 ml), and 10N-HCl/dioxane (10 ml) was added thereto with stirring under ice cooling, further followed by stirring for 10 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. This was dissolved in DMF (5 ml), and the resulting solution was added dropwise to DMF (100 ml) containing TEA (6.96 ml), followed by stirring overnight. The solvent was removed by distillation, and the residue was dissolved in AcOEt. The solution was washed successively with 10% aqueous citric acid, 5% aqueous NaHCO3 and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and the residue was purified by silica gel chromatography (Merck Kiesel Gel 60. 1% methanol/chloroform). Then, ether-petroleum ether was added thereto to separate out a precipitate, which was collected by filtration and dried under reduced pressure.
Yield: 847 mg (82.6%), Rf1 : 0.40, Rf2 : 0.74
(6) Production of cyclo[-D-Asp-Hyp(Bzl)-Asp-D-Leu-Leu-D-Trp-]
Cyclo[-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-D-Trp-] (103 mg) was dissolved in DMF (10 ml), and palladium black (100 mg) was added thereto. The mixture was vigorously stirred in a stream of hydrogen at room temperature for 1 hour. The catalyst was removed by filtration, and the filtrate was concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The yield was 64 mg (82.6%). Of this precipitate, 30.0 mg was purified by reversed phase liquid chromatography [column: YMC-D-ODS-5 (2 cm×25 cm)]. The yield was 23.7 mg (79.0%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.97(2); Hyp 0.84 (1) LSIMS (M+H+)=846, (theoretical value)=846
EXAMPLE 14
Production of cyclo[-D-Asp-Hyp-Asp-D-Leu-Leu-D-Trp-]
Cyclo[-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-D-Leu-Leu-D-Trp-] (103 mg) was dissolved in DMF (10 ml), and palladium black (100 mg) was added thereto. The mixture was vigorously stirred in a stream of hydrogen at room temperature for 1 hour. The catalyst was removed by filtration, and the filtrate was concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried Under reduced pressure. The resulting product was dissolved in methanol (10 ml), and palladium black (100 mg) was added thereto. The mixture was vigorously stirred overnight in a stream of hydrogen at room temperature. The catalyst was removed by filtration, and the filtrate was concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried under reduced pressure. The yield was 65 mg (85.7%). Of this precipitate, 25.0 mg was purified by reversed phase liquid chromatography [column: YMC-D-ODS-5 (2 cm×25 cm)]. The yield was 19.7 mg (78.8%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.00(2); Hyp 0.97 (1) LSIMS (M+H+)=756, (theoretical value)=756
EXAMPLE 53
Production of cyclo[-D-Asp-Trp-Asp-D-tLeu-Leu-D-Trp-]
(1) Production of Boc-Asp(OBzl)-OPac
Boc-Asp(OBzl)-OH (32.3 g) and Cs2 CO3 (16.3 g) were dissolved in 90% aqueous methanol, and the solution was concentrated. The residue was dissolved in DMF (300 ml), and phenacyl bromide (21.9 g) was added thereto, followed by stirring overnight. The resulting CsBr was separated by filtration, and the filtrate was concentrated. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3 and 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, the residue was recrystallized from ethyl acetate-petroleum ether.
Yield: 42.9 g (97.1%), Melting point: 73°-74° C., Rf1 : 0.69, Rf2 : 0.82 [α]D 28 -21.8° (c=0.99, in DMF)
Elemental analysis: As C24 H27 NO7 Calculated: C, 65.29; H, 6.16; N, 3.17 Found: C, 65.42; H, 6.25; N, 3.32
(2) Production of Boc-Trp-Asp(OBzl)-OPac
Boc-Trp-OH (12.2 g) was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (4.4 ml) was added thereto, and subsequently, IBCF (5.4 ml) was added. After 2 minutes, a DMF solution of HCl.H-Asp(OBzl)-OPac and N-methylmorpholine was added. HCl.H-Asp(OBzl)-OPac was obtained by dissolving Boc-Asp(OBzl)-OPac (17.7 g) in 8N-HCl/dioxane (100 ml), stirring the solution under ice cooling for 30 minutes, followed by concentration, and adding ether to precipitate crystals, which were collected by filtration and dried. After stirring at -15° C. for 30 minutes, the solution was brought to room temperature. After 30 minutes, the resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 23.9 g (95.2%), Melting point: 73°-74° C., Rf1 : 0.40, Rf2 : 0.69 [α]D 28 -20.6° (c=1.05, in DMF)
Elemental analysis: As C35 H37 N3 O8 Calculated: C, 66.97; H, 5.94; N, 6.69 Found: C, 67.21; H, 6.13; N, 6.71
(3) Production of Boc-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Trp-Asp(OBzl)-OPac (50.2 g) to dissolve it, and the solution was stirred under ice cooling for 30 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (80 ml), and the solution was cooled with ice, followed by addition of TEA (22.3 ml). Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (28.5 g), HONB (17.2 g) and DCC (19.8 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 60.3 g (90.5%), Melting point: 95°-97° C., Rf1 : 0.40, Rf2 : 0.70 [α]D 28 -5.2° (c=1.14, in DMF)
Elemental analysis: As C46 H48 N4 O11 Calculated: C, 66.33; H, 5.81; N, 6.73 Found: C, 66.40; H, 5.93; N, 6.84
(4) Production of Boc-D-Trp-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (59.1 g) to dissolve it, and the solution was stirred under ice cooling for 40 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (70 ml), and the solution was cooled with ice, followed by addition of TEA (19.8 ml). Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (23.8 g), HONB (15.3 g) and DCC (17.6 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 58.1 g (80.3%), Melting point: 139°-140° C., Rf1 : 0.38, Rf2 : 0.70 [α]D 28 -3.0° (c=1.29, in DMF)
Elemental analysis: As C57 H58 N6 O12 Calculated: C, 67.18; H, 5.74; N, 8.25 Found: C, 67.28; H, 5.87; N, 8.34
(5) Production of Boc-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (20.4 g) to dissolve it, and the solution was stirred under ice cooling for 30 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (20 ml), and the solution was cooled with ice, followed by addition of TEA (5.6 ml). Boc-Leu-ONB [prepared from Boc-Leu-OH.H2 O (5.48 g), HONB (4.30 g) and DCC (4.95 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. The resulting residue was recrystallized from ethyl acetate-petroleum ether.
Yield: 18.6 g (82.2%), Melting point: 119°-120° C., Rf1 : 0.39, Rf2 : 0.70 [α]D 28 -9.1° (c=0.98, in DMF)
Elemental analysis: As C63 H69 N7 O13 Calculated: C, 66.83; H, 6.14; N, 8.66 Found: C, 66.80; H, 6.38; N, 8.75
(6) Production of Boc-D-tLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (1.02 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (5 ml), and the solution was cooled with ice, followed by addition of TEA (0.25 ml). Boc-D-tLeu-OH (0.23 g), HONB (0.15 g) and DCC (0.22 g)] were added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.08 g (96.4%), Melting point: 124°-126° C., Rf1 : 0.34, Rf2 : 0.71 [α]D 28 -6.1° (c=1.27, in DMF)
Elemental analysis: As C69 H80 N8 O14 Calculated: C, 66.54; H, 6.47; N, 9.00 Found: C, 66.67; H, 6.60; N, 9.21
(7) Production of Boc-D-tLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH
Boc-D-tLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.75 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.66 g (97.6%), Melting point: 125°-127° C., Rf1 : 0.03, Rf2 : 0.67 [α]D 25 -5.5° (c=1.19, in DMF)
Elemental analysis: As C61 H74 N8 O13 Calculated: C, 64.99; H, 6.62; N, 9.94 Found: C, 65.11; H, 6.78; N, 10.01
(8) Production of cyclo[-D-Asp-Trp-Asp-D-tLeu-Leu-D-Trp-]
Boc-D-tLeu-Leu-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.34 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 101 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 12.4 mg (42.8%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.29(1) LSIMS (M+H+)=829, (theoretical value)=829
EXAMPLE 54
Production of cyclo[-D-Asp-Trp-Asp-D-γMeLeu-Leu-D-Trp-]
(1) Production of Boc-D-γMeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (1.02 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (5 ml), and the solution was cooled with ice, followed by addition of TEA (0.25 ml). Boc-D-γMeLeu-OH (0.24 g), HONB (0.15 g) and DCC (0.22 g)] were added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.11 g (98.0%), Melting point: 171°-172° C., Rf1 : 0.32, Rf2 : 0.70 [α]D 28 -5.4° (c=1.12, in DMF)
Elemental analysis: As C70 H82 N8 O14 Calculated: C, 66.76; H, 6.56; N, 8.90 Found: C, 66.88; H, 6.69; N, 9.09
(2) Production of Boc-D-γMeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH
Boc-D-γMeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.76 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.67 g (97.8%), Melting point: 115°-117° C., Rf1 : 0.03, Rf2 : 0.67 [α]D 28 +6.3° (c=1.24, in DMF)
Elemental analysis: As C62 H76 N8 O13 Calculated: C, 65.25; H, 6.71; N, 9.82 Found: C, 65.18; H, 6.87; N, 9.85
(3) Production of cyclo[-D-Asp-Trp-Asp-D-γMeLeu-Leu-D-Trp-]
Boc-D-γMeLeu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.34 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 102 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was separated by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 16.1 mg (51.5%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.25(1) LSIMS (M+H+)=843, (theoretical value)=843
EXAMPLE 55
Production of cyclo[-D-Asp-Trp-Asp-D-Thg(2)-Leu-D-Trp-]
(1) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (1.02 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (5 ml), and the solution was cooled with ice, followed by addition of TEA (0.25 ml). Boc-D-Thg(2)-OH (0.19 g), HONB (0.15 g) and DCC (0.22 g)] were added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.04 g (90.9%), Melting point: 130°-132° C., Rf1 : 0.32, Rf2 : 0.68 [α]D 28 -5.9° (c=0.95, in DMF)
Elemental analysis: As C69 H74 N8 O14 S Calculated: C, 65.18; H, 5.87; N, 8.81; S, 2.52 Found: C, 65.39; H, 5.99; N, 8.94; S, 2.46
(2) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.76 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.68 g (98.3%), Melting point: 167°-169° C., Rf1 : 0.03, Rf2 : 0.68 [α]D 28 -5.3° (c=0.99, in DMF)
Elemental analysis: As C61 H68 N8 O13 S Calculated: C, 63.53; H, 5.94; N, 9.72; S, 2.78 Found: C, 63.42; H, 6.04; N, 9.90; S, 2.82
(3) Production of cyclo[-D-Asp-Trp-Asp-D-Thg(2)-Leu-D-Trp-]
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. The residue was purified using silica gel chromatography (1.5% methanol/DCM), and subsequently, ether was added thereto to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 104 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) to obtain a desired material. The yield was 11.7 mg (4.6%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.30(1) LSIMS (M+H+)=855, (theoretical value)=855
EXAMPLE 56
Production of cyclo[-D-Asp-Trp-Asp-Acbu-Leu-D-Trp-]
(1) Production of Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (1.02 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (5 ml), and the solution was cooled with ice, followed by addition of TEA (0.25 ml). Boc-Acbu-OH (0.20 g), HONB (0.15 g) and DCC (0.22 g) were added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 1.06 g (94.0%), Melting point: 141°-143° C., Rf1 : 0.27, Rf2 : 0.67 [α]D 28 -10.6° (c=1.27, in DMF)
Elemental analysis: As C68 H76 N8 O14 Calculated: C, 66.43; H, 6.23; N, 9.11 Found: C, 66.42; H, 6.33; N, 9.30
(2) Production of Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH
Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OPac (0.74 g) was dissolved in 90% aqueous AcOH (10 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.65 g (97.5%), Melting point: 114°-116° C., Rf1 : 0.03, Rf2 : 0.67 [α]D 28 -12.50 (c=1.02, in DMF)
Elemental analysis: As C60 H70 N8 O13 Calculated: C, 64.85; H, 6.35; N, 10.08 Found: C, 64.92; H, 6.42; N, 10.01
(3) Production of cyclo[-D-Asp-Trp-Asp-Acbu-Leu-D-Trp-]
Boc-Acbu-Leu-D-Trp-D-Asp(OBzl)-Trp-Asp(OBzl)-OH (0.33 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 15 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 99 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) to obtain a desired material. The yield was 2.2 mg (10.4%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.23(1) LSIMS (M+H+)=813, (theoretical value)=813
EXAMPLE 79
Production of cyclo[-D-Asp-Orn(COPh)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-D-Asp(OBzl)-OPac
Boc-D-Asp(OBzl)-OH (25.0 g) was dissolved in methanol (50 ml), and Cs2 CO3 (12.6 g) was added thereto little by little with stirring at room temperature. After Cs2 CO3 was dissolved, the solvent was removed by distillation, and the residue was dissolved in DMF (500 ml). A DMF solution (50 ml) of phenacyl bromide (15.4 g) was added thereto dropwise with stirring under ice cooling, further followed by stirring at room temperature for 1 hour. Precipitated CsBr was removed by filtration,and the solvent was removed by distillation. The residue was dissolved in AcOEt, and the solution was washed successively with 5% aqueous NaHCO3, 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and the residue was recrystallized from ethyl acetate-petroleum ether.
Yield: 31.8 g (93.2%), Melting point: 74.0°-75.0° C., Rf1 : 0.73, Rf2 : 0.86 [α]D 25 21.9° (c=1.00, in DMF)
Elemental analysis: As C24 H27 NO7 Calculated: C, 65.29; H, 6.16; N, 3.17 Found: C, 65.03; H, 6.19; N, 3.14
(2) Production of Boc-D-Trp-D-Asp(OBzl)-OPac
Boc-D-Asp(OBzl)-OPac (26.5 g) was dissolved in dioxane (50 ml), and 10N-HCl/dioxane (28.6 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to form a precipitate, which was collected by filtration, thereby obtaining H-D-Asp(OBzl)-OPac hydrochloride.
Boc-D-Trp-OH (18.3 g) was dissolved in distilled THF (150 ml), and N-methylmorpholine was added thereto with stirring at room temperature. After the atmosphere was replaced with nitrogen, isobutyl chloroformate (7.88 ml) was slowly added dropwise thereto with stirring at -15° C., and stirring was further continued at -15° C. for 15 minutes, thereby obtaining mixed acid anhydrides. An amine component [prepared by dissolving H-D-Asp(OBzl)-OPac hydrochloride in DMF (100 ml) and adding N-methylmorpholine (6.62 ml) thereto with stirring at -15° C. for neutralization] was added thereto little by little with stirring at -15° C., and the mixture was further stirred at room temperature for 1 hour. The solvent was removed by distillation, and the residue was dissolved in AcOEt. The solution was washed successively with 5% aqueous NaHCO3, 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and the residue was recrystallized from ethyl acetate-petroleum ether.
Yield: 36.1 g (96.0%), Melting point: 75.0°-76.0° C., Rf1 : 0.34, Rf2 : 0.73 [α]D 25 19.1° (c=1.00, in DMF)
Elemental analysis: As C35 H37 N3 O8 Calculated: C, 66.97; H, 5.94; N, 6.69 Found: C, 67.19; H, 6.20; N, 6.44
(3) Production of Boc-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-D-Trp-D-Asp(OBzl)-OPac (34.5 g) was dissolved in dioxane (50 ml), and 10N-HCl/dioxane (100 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (350 ml), and TEA was added thereto with stirring under ice cooling to neutralize it. A DMF solution (50 ml) of Boc-Leu-ONB prepared from Boc-Leu-OH (15.3 g), HONB (13.8 g) and DCC (17.0 g) was further added thereto, followed by stirring overnight at room temperature. The solvent was removed by distillation, and the residue was dissolved in AcOEt. N,N-Dimethylpropanediamine (2.5 ml) was added thereto, followed by stirring at room temperature for 30 minutes. The mixture was washed successively with 5% aqueous NaHCO3, 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 37.49 g (92.0%), Melting point: 72°-74° C., Rf1 : 0.28, Rf2 : 0.71 [α]D 25 28.3° (c=1.00, in DMF)
Elemental analysis: As C41 H48 N4 O9 Calculated: C, 66.47; H, 6.53; N, 7.56 Found: C, 66.25; H, 6.68; N, 7.56
(4) Production of Boc-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-Leu-D-Trp-D-Asp(OBzl)-OPac (29.6 g) was dissolved in dioxane (40 ml), and 10N-HCl/dioxane (100 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (300 ml), and TEA was added thereto with stirring under ice cooling to neutralize it. A DMF solution (40 ml) of Boc-D-Leu-ONB prepared from Boc-D-Leu-OH.H2 O (11.0 g), HONB (8.60 g) and DCC (10.7 g) was further added thereto, followed by stirring overnight at room temperature. The solvent was removed by distillation, and the residue was dissolved in AcOEt. N,N-Dimethylpropanediamine (1.26 ml) was added thereto, followed by stirring at room temperature for 30 minutes. The mixture was washed successively with 5% aqueous NaHCO3, 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 30.9 g (90.5%), Melting point: 79°-80° C., Rf1 : 0.26, Rf2 : 0.73 [α]D 25 27.4° (c=1.00, in DMF)
Elemental analysis: As C47 H59 N5 O10 Calculated: C, 66.10; H, 6.96; N, 8.20 Found: C, 66.11; H, 7.05; N, 8.05
(5) Production of Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (17.1 g) was dissolved in dioxane (10 ml), and 10-N HCl/dioxane (50 ml) was added thereto under ice cooling, followed by stirring under ice cooling for 30 minutes. The solvent was removed by distillation at room temperature, and ether was added to the residue to separate out a precipitate, which was collected by filtration. The resulting precipitate was dissolved in DMF (100 ml), and TEA was added thereto with stirring under ice cooling to neutralize it. A DMF solution (20 ml) of Boc-Asp(OBzl)-ONB prepared from Boc-Asp(OBzl)-OH (7.76 g), HONB (5.02 g) and DCC (6.19 g) was further added thereto, followed by stirring overnight at room temperature. The solvent was removed by distillation, and the residue was dissolved in AcOEt. N,N-Dimethylpropanediamine (0.63 ml) was added thereto, followed by stirring at room temperature for 30 minutes. The mixture was washed successively with 5% aqueous NaHCO3, 10% aqueous citric acid and a saturated aqueous solution of sodium chloride. After drying with Na2 SO4, the solvent was removed by distillation, and then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. The precipitate was recrystallized from ethyl acetate-petroleum ether.
Yield: 16.5 g (82.5%), Melting point: 178°-179° C., Rf1 : 0.28, Rf2 : 0.76 [α]D 25 13.0° (c=1.00, in DMF)
Elemental analysis: As C58 H70 N6 O13 Calculated: C, 65.77; H, 6.66; N, 7.93 Found: C, 65.49; H, 6.69; N, 8.02
(6) Production of Boc-Orn(COPh)-OH.DCHA
Boc-Orn-OH (0.51 g) [obtained by catalytically reducing Boc-Orn(Z)-OH in methanol in a stream of hydrogen using 10% Pd-carbon as a catalyst] was dissolved in DMF, and the solution was cooled with ice. TEA (0.61 ml) and PhCOONB [prepared from PhCOOH (0.30 g), HONB (0.47 g) and DCC (0.54 g)] were added thereto, followed by stirring overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether and dicyclohexylamine (438 μl) were added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.01 g (97.6%), Melting point: 148°-150° C. [α]D 28 +9.6° (c=0.90, in methanol)
Elemental analysis: As C29 H47 N3 O5 Calculated: C, 67.28; H, 9.15; N, 8.12 Found: C, 67.35; H, 8.99; N, 8.03
(7) Production of Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) obtained in (5) described above was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml). Boc-Orn(COPh)-ONB [prepared from Boc-Orn(COPh)-OH (0.30 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 0.97 g (94.9%), Melting point: 107°-109° C., Rf1 : 0.28, Rf2 : 0.64 [α]D 28 +8.2° (c=1.23, in DMF)
Elemental analysis: As C70 H84 N8 O15 Calculated: C, 65.81; H, 6.63; N, 8.77 Found: C, 65.76; H, 6.76; N, 8.93
(8) Production of Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH
Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.77 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.68 g (97.8%), Melting point: 113°-115° C., Rf1 : 0.02, Rf2 : 0.63 [α]D 28 +9.8° (c=1.10, in DMF)
Elemental analysis: As C62 H78 N8 O14 Calculated: C, 64.23; H, 6.78; N, 9.67 Found: C, 64.11; H, 6.90; N, 9.52
(9) Production of cyclo[-D-Asp-Orn(COPh)-Asp-D-Leu-Leu-D-Trp-]
Boc-Orn(COPh)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours, Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 104 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 11.1 mg (48.1%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.19(2); Orn 1.09(1) LSIMS (M+H+)=861, (theoretical value)=861
EXAMPLE 80
Production of cyclo[-D-Asp-Orn(COCH2 Ph)-AsP-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Orn(COCH2 Ph)-OH.CHA
Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice. TEA (1.53 ml) and PhCH2 COCl (367 μl) was added thereto, and stirred for 2 hours. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether and cyclohexylamine (254 μl) were added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.52 g (57.9%), Melting point: 137°-139° C. [α]D 28 +2.4° (c=0.50, in methanol)
Elemental analysis: As C24 H39 N3 O5 Calculated: C, 64.12; H, 8.74; N, 9.35 Found: C, 64.05; H, 8.92; N, 9.39
(2) Production of Boc-Orn(COCH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml). Boc-Orn(COCH2 Ph)-ONB [prepared from Boc-Orn(COCH2 Ph)-OH (0.32 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 0.81 g (78.4%), Melting point: 148°-150° C., Rf1 : 0.34, Rf2 : 0.65 [α]D 28 14.1° (c=1.13, in DMF)
Elemental analysis: As C71 H86 N8 O15 Calculated: C, 66.03; H, 6.71; N, 8.68 Found: C, 66.14; H, 6.67; N, 8.51
(3) Production of Boc-Orn(COCH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH
Boc-Orn(COCH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.65 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.63 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.57 g (97.2%), Melting point: 120°-122° C., Rf1 : 0.03, Rf2 : 0.64 [α]D 28 +16.9° (c=0.91, in DMF)
Elemental analysis: As C63 H80 N8 O14 Calculated: C, 64.49; H, 6.87; N, 9.55 Found: C, 64.60; H, 6.79; N, 9.36
(4) Production of cyclo[-D-Asp-Orn(COCH2 Ph)-Asp-D-Leu-Leu-D-Trp-]
Boc-Orn(COCH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (10 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 106 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 2.3 mg (2.9%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.29(2); Orn 1.10(1) LSIMS (M+H+)=876, (theoretical value)=876
EXAMPLE 81
Production of cyclo[-D-Asp-Orn(COCH2 CH2 Ph)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Orn(COCH2 CH2 Ph)-OH.DCHA
Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice. TEA (0.61 ml) and PhCH2 CH2 COONB [prepared from PhCH2 CH2 COOH (0.36 g), HONB (0.47 g) and DCC (0.54 g)] was added thereto, and stirred overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether and dicyclohexylamine (438 μl) were added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.72 g (66.1%), Melting point: 131°-133° C. [α]D 28 +6.9° (c=0.86, in methanol)
Elemental analysis: As C31 H51 N3 O5 Calculated: C, 68.22; H, 9.42; N, 7.70 Found: C, 68.29; H, 9.22; N, 7.62
(2) Production of Boc-Orn(COCH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml). Boc-Orn(COCH2 CH2 Ph)-ONB [prepared from Boc-Orn(COCH2 CH2 Ph)-OH (0.33 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 0.95 g (91.0%), Melting point: 110°-112° C., Rf1 : 0.23, Rf2 : 0.65 [α]D 28 +9.0° (c=0.98, in DMF)
Elemental analysis: As C72 H88 N8 O15 Calculated: C, 66.24; H, 6.79; N, 8.58 Found: C, 66.07; H, 6.90; N, 8.75
(3) Production of Boc-Orn(COCH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH
Boc-Orn(COCH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.78 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.70 g (98.3%), Melting point: 105°-108° C., Rf1 : 0.02, Rf2 : 0.64 [α]D 28 +10.4° (c=1.20, in DMF)
Elemental analysis: As C64 H82 N8 O14 Calculated: C, 64.74; H, 6.96; N, 9.44 Found: C, 64.60; H, 7.07; N, 9.64
(4) Production of cyclo[-D-Asp-Orn(COCH2 CH2 Ph)-Asp-D-Leu-Leu-D-Trp-]
Boc-Orn(COCH2 CH2 Ph)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 107 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 9.1 mg (40.9%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.22(2); Orn 1.10(1) LSIMS (M+H+)=889, (theoretical value)=889
EXAMPLE 82
Production of cyclo[-D-Asp-Orn(COCH2 -Ind)-Asp-D-Leu-Leu-D-Trp-]
(1) Production of Boc-Orn(COCH2 -Ind)-OH.DCHA
Boc-Orn-OH (0.51 g) was dissolved in DMF, and the solution was cooled with ice. TEA (0.61 ml) and Ind-CH2 COONB [prepared from Ind-CH2 COOH (0.42 g), HONB (0.47 g) and DCC (0.54 g)] was added thereto, and stirred overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether and cyclohexylamine (254 μl) were added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.10 g (96.5%), Melting point: 95°-98° C. [α]D 28 +5.3° (c=0.92, in methanol)
Elemental analysis: As C32 H50 N4 O5 Calculated: C, 67.34; H, 8.83; N, 9.82 Found: C, 67.25; H, 9.00; N, 9.93
(2) Production of Boc-Orn(COCH2 -Ind)-AsP(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac
Boc-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.85 g) prepared in EXAMPLE 79 (5) was dissolved in 8N-HCl/dioxane (15 ml), and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added thereto to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml), and the solution was cooled with ice, followed by addition of TEA (0.22 ml). Boc-Orn(COCH2 -Ind)-ONB [prepared from Boc-Orn(COCH2 -Ind)-OH (0.35 g), HONB (0.18 g) and DCC (0.21 g)] was added thereto, and the mixture was stirred overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 0.93 g (87.4%), Melting point: 109°-111° C., Rf1 : 0.16, Rf2 : 0.64 [α]D 28 +9.7° (c=1.01, in DMF)
Elemental analysis: As C73 H87 N8 O15 Calculated: C, 65.90; H, 6.59; N, 9.47 Found: C, 65.69; H, 6.89; N, 9.47
(3) Production of Boc-Orn(COCH2 -Ind)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH
Boc-Orn(COCH2 -Ind)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OPac (0.80 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.71 g (97.6%), Melting point: 96°-98° C., Rf1 : 0.02, Rf2 : 0.62 [α]D 28 +9.4° (c=1.01, in DMF)
Elemental analysis: As C65 H81 N9 O14 Calculated: C, 64.39; H, 6.73; N, 10.40 Found: C, 64.51; H, 6.86; N, 10.36
(4) Production of cyclo[-D-Asp-Orn(COCH2 -Ind)-Asp-D-Leu-Leu-D-Trp-]
Boc-Orn(COCH2 -Ind)-Asp(OBzl)-D-Leu-Leu-D-Trp-D-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (20 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (20 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 109 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) to obtain a desired material. The yield was 4.1 mg (12.5%).
Anal. for amino acids [6N-HCl, 110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 2.25(2); Orn 1.08(1) LSIMS (M+H+)=915, (theoretical value)=915
EXAMPLE 88
Production of cyclo[-D-Asp-Hyp(Bzl)-Asp-D-Thg(2)-Leu-D-Trp-]
(1) Production of Boc-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Hyp(Bzl)-Asp(OBzl)-OPac (3.77 g) prepared in accordance with the processes described in EXAMPLE 53 (1) and (2) to dissolve it, and the solution was stirred under ice cooling for 30 minutes, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4, concentrated and dried. The resulting product was dissolved in DMF (40 ml) and cooled with ice. Then, TEA (0.84 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. The residue was purified using silica gel chromatography (1% methanol/DCM) and subsequently concentrated. The yield was 2.22 g (57.4%).
(2) Production of Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac (1.67 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. 4% aqueous NaHCO3 was added thereto to adjust the pH to 9-10, and then, extraction was conducted using AcOEt. The extract was dried with Na2 SO4, concentrated and dried. The resulting product was dissolved in DMF (20 ml) and cooled with ice. Then, TEA (0.28 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 2.05 g (98.9%), Melting point: 76°-78° C., Rf1 : 0.48, Rf2 : 0.72 [α]D 28 +9.2° (c=1.13, in DMF)
Elemental analysis: As C58 H61 N5 O13 Calculated: C, 67.23; H, 5.93; N, 6.76 Found: C, 67.04; H, 6.14; N, 6.79
(3) Production of Boc-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac
8-N HCl/dioxane was added to Boc-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac (1.04 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The resulting product was dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.28 ml) was added thereto. Boc-Leu-ONB [prepared from Boc-Leu-OH.H2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.09 g (94.8%), Melting point: 88°-90° C., Rf1 : 0.50, Rf2 : 0.71 [α]D 28 +0.6° (c=0.88, in DMF)
Elemental analysis: As C64 H72 N6 O14 Calculated: C, 66.88; H, 6.31; N, 7.31 Found: C, 66.91; H, 6.61; N, 7.51
(4) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac (0.92 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The resulting product was dissolved in DMF (10 ml) and cooled with ice. Then, TEA (0.22 ml) was added thereto. Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.01 g (98.0%), Melting point: 94°-97° C., Rf1 : 0.41, Rf2 : 0.70 [α]D 28 -0.1° (c=0.78, in DMF)
Elemental analysis: As C70 H77 N7 O15 S Calculated: C, 65.25; H, 6.02; N, 7.61; S, 2.49 Found: C, 65.40; H, 6.13; N, 7.75; S, 2.30
(5) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OH
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OPac (0.77 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.70 g (99.7%), Melting point: 108°-110° C., Rf1 : 0.33, Rf2 : 0.65 [α]D 28 +4.6° (c=1.15, in DMF)
Elemental analysis: As C62 H71 N7 O14 S Calculated: C, 63.63; H, 6.11; N, 8.38; S, 2.74 Found: C, 63.83; H, 6.23; N, 8.49; S, 2.45
(6) Production of cyclo[-D-Asp-Hyp(Bzl)-Asp-D-Thg(2)-Leu-D-Trp-]
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Hyp(Bzl)-Asp(OBzl)-OH (0.35 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 74 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 4.7 mg (5.7%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Leu 1.18(1) LSIMS (M+H+)=872, (theoretical value)=872
EXAMPLE 89
Production of cyclo[-D-Asp-Glu(Bzl)-Asp-D-Thg(2)-Leu-D-Trp-]
(1) Production of Boc-Glu(Bzl)-OBzl
Boc-Glu-OBzl (1.17 g, purchased from Watanabe Kagaku) was dissolved in acetonitrile (50 ml), and HONB (0.68 g) and DCC (0.79 g) were added thereto, followed by stirring for 2 hours under ice cooling. The resulting insoluble material was separated by filtration, and benzylamine (0.76 ml) was added thereto, followed by stirring overnight. After concentration of the reaction solution, the residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.37 g (92.6%), Melting point: 91.5°-92.5° C., Rf1 : 0.36, Rf2 : 0.69 [α]D 25 -16.5° (c=1.02, in DMF)
Elemental analysis: As C24 H30 N2 O5 Calculated: C, 67.59; H, 7.09; N, 6.57 Found: C, 67.44; H, 7.20; N, 6.68
(2) Production of Boc-Gln(Bzl)-Asp(OBzl)-OPac
Boc-Gln(Bzl)-OH (3.36 g) [prepared by catalytically reducing Boc-Gln(Bzl)-OBzl (4.26 g) in methanol (20 ml) in a stream of hydrogen at ordinary temperature and pressure in the presence of 10% Pd-carbon (20 mg)] was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (1.1 ml) was added thereto, and subsequently, IBCF (1.3 ml) was added. After 2 minutes, a DMF solution of HCl.Asp(OBzl)-OPac and N-methylmorpholine (1.1 ml) was added. HCl.Asp(OBzl)-OPac was obtained by dissolving Boc-Asp(OBzl)-OPac (4.41 g) in 8-N HCl/dioxane (50 ml), stirring the solution under ice cooling for 30 minutes, followed by concentration, and adding ether to precipitate crystals, which were collected by filtration and dried. After stirring at -15° C. for 30 minutes, the solution was brought to room temperature. After 30 minutes, the resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 5.11 g (77.5%), Melting point: 148.5°-150.0° C., Rf1 : 0.41, Rf2 : 0.64 [α]D 28 -13.4° (c=1.00, in DMF)
Elemental analysis: As C36 H41 N3 O9 Calculated: C, 65.54; H, 6.26; N, 6.37 Found: C, 65.38; H, 6.25; N, 6.34
(3) Production of Boc-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Gln(Bzl)-Asp(OBzl)-OPac (3.96 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (40 ml) and cooled with ice. Then, TEA (1.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 4.56 g (87.9%), Melting point: 140°-141° C., Rf1 : 0.42, Rf2 : 0.69 [α]D 28 -2.0° (c=1.02, in DMF)
Elemental analysis: As C47 H52 N4 O12 Calculated: C, 65.27; H, 6.06; N, 6.48 Found: C, 65.05; H, 6.13; N, 6.67
(4) Production of Boc-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac (1.73 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (20 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ethyl acetate was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.98 g (94.2%), Melting point: 194°-196° C., Rf1 : 0.36, Rf2 : 0.67 [α]D 28 +1.6° (c=0.93, in DMF)
Elemental analysis: As C58 H62 N6 O13 Calculated: C, 66.27; H, 5.95; N, 7.99 Found: C, 66.14; H, 6.03; N, 8.07
(5) Production of Boc-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac (1.05 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.28 ml) was added thereto. Boc-Leu-ONB [prepared from Boc-Leu-OH.H2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.04 g (89.3%), Melting point: 175°-177° C., Rf1 : 0.38, Rf2 : 0.68 [α]D 28 +0.35° (c=0.85, in DMF)
Elemental analysis: As C64 H73 N7 O14 Calculated: C, 66.02; H, 6.32; N, 8.42 Found: C, 65.94; H, 6.43; N, 8.48
(6) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac (0.93 g) to dissolve it, and the solution was stirred under ice cooling for 15 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (5 ml) and cooled with ice. Then, TEA (0.22 ml) was added thereto. Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.02 g (97.9%), Melting point: 170°-172° C., Rf1 : 0.30, Rf2 : 0.69 [α]D 28 +3.6° (c=0.83, in DMF)
Elemental analysis: As C70 H78 N8 O15 S Calculated: C, 64.50; H, 6.03; N, 18.60; S, 2.46 Found: C, 64.52; H, 6.15; N, 8.77; S, 2.41
(7) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OH
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OPac (0.78 g) was dissolved in 90% aqueous AcOH (15 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.67 g (94.2%), Melting point: 145°-147° C., Rf1 : 0.22, Rf2 : 0.66 [α]D 28 +6.6° (c=1.00, in DMF).
Elemental analysis: As C62 H72 N8 O14 S Calculated: C, 62.82; H, 6.12; N, 9.45; S, 2.71 Found: C, 62.93; H, 6.24; N, 9.62; S, 2.44
(8) Production of cyclo[-D-Asp-Gln(Bzl)-Asp-D-Thg(2)-Leu-D-Trp-]
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Gln(Bzl)-Asp(OBzl)-OH (0.36 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8N-HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.42 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 75 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 5.0 mg (8.8%).
Anal for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 2.00(2); Glu 1.08 (1); Leu 1.09(1) LSIMS (M+H+)=887, (theoretical value)=887
EXAMPLE 90
[A] Production of cyclo[-D-Asp-Asn(CH2 CH2 -Ind)-Asp-DThg-(2)-Leu-D-Trp-]
(1) Production of Boc-Asn(CH2 CH2 -Ind)-OBzl
Boc-Asp(ONB)-OBzl [prepared from Boc-Asp-OBzl (14.23 g), HONB (8.68 g) and DCC (9.99 g)] was added to tryptamine hydrochloride (7.87 g) together with TEA (8.4 ml) in DMF (150 ml) under ice-cooling, and the mixture was stirred overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to give crystals, which were collected by filtration.
Yield: 17.1 g (92.0%), Melting point: 96°-97° C., Rf1 : 0.41, Rf2 : 0.70 [α]D 28 -9.8° (c=1.24, in DMF)
Elemental analysis: As C26 H30 N3 O5 Calculated: C, 67.22; H, 6.51; N, 9.05 Found: C, 67.31; H, 6.44; N, 8.97
(2) Production of Boc-Asn(CH2 CH2 -Ind)-OH.CHA
Boc-Asn(CH2 CH2 -Ind)-OBzl (4.6 g) was dissolved in methanol (100 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in ether-AcOEt (1:1), and CHA (1.1 ml) was added thereto to precipitate crystals, which were collected by filtration. The crystals were recrystallized from methanol-ether to obtain a desired material.
Yield: 4.1 g (88.9%), Melting point: 178°-179° C., Rf2 : 0.37 [α]D 28 +7.5° (c=1.17, in methanol)
Elemental analysis: As C25 H37 N4 O5 Calculated: C, 63.13; H, 8.26; N, 11.78 Found: C, 63.11; H, 8.22; N, 11.78
(3) Production of Boc-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac
Boc-Asn(CH2 CH2 -Ind)-OH [prepared from Boc-Asn(CH2 CH2 -Ind)-OH.CHA (3.7 g)] was dissolved in THF, and the solution was cooled to -15° C. with stirring. Then, N-methylmorpholine (0.9 ml) was added thereto, and subsequently, IBCF (1.1 ml) was added. After 2 minutes, a DMF solution of HCl.Asp(OBzl)-OPac and N-methylmorpholine was added. HCl.Asp(OBzl)-OPac was obtained by dissolving Boc-Asp(OBzl)-OPac (3.5 g) in 8-N HCl/dioxane (20 ml), stirring the solution under ice cooling for 30 minutes, followed by concentration, and adding ether to precipitate crystals, which were collected by filtration and dried. After stirring at -15° C. for 30 minutes, the solution was brought to room temperature. After 30 minutes, the resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with=water, the solution was dried with Na2 SO4 and concentrated. Ether was added to the resulting residue to separate out a precipitate, which was collected by filtration.
Yield: 4.3 g (79.2%), Melting point: 142°-143° C., Rf1 : 0.38, Rf2 : 0.69 [α]D 28 -8.0° (c=0.97, in DMF)
Elemental analysis: As C38 H41 N4 O9 Calculated: C, 65.41; H, 5.92; N, 8.03 Found: C, 65.46; H, 5.95; N, 7.89
(4) Production of Boc-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac (4.09 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (40 ml) and cooled with ice. Then, TEA (1.67 ml) was added thereto. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (2.16 g), HONB (1.31 g) and DCC (1.51 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 4.84 g (89.2%), Melting point: 92°-94° C., Rf1 : 0.41, Rf2 : 0.67 [α]D 28 -7.4° (c=1.11, in DMF)
Elemental analysis: As C49 H53 N5 O12 Calculated: C, 65.10; H, 5.91; N, 7.75 Found: C, 64.85; H, 5.97; N, 7.93
(5) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac (1.77 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (20 ml) and cooled with ice. Then, TEA (0.56 ml) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (0.67 g), HONB (0.43 g) and DCC (0.50 g)] was added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with NagSO4 and concentrated. Then, the residue was purified using silica gel chromatography (2% methanol/DCM). Subsequently, petroleum ether was added thereto to separate out a precipitate, which was collected by filtration.
Yield: 1.24 g (56.9%), Melting point: 139°-140° C., Rf1 : 0.34, Rf2 : 0.67 [α]D 28 -0.1° (c=0.92, in DMF)
Elemental analysis: As C60 H63 N7 O13 Calculated: C, 66.10; H, 5.82; N, 8.99 Found: C, 65.98; H, 5.83; N, 8.95
(6) Production of Boc-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac
8-N HCl/dioxane was added to Boc-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac (1.09 g) to dissolve it, and the solution was stirred under ice cooling for 30 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (15 ml) and cooled with ice. Then, TEA (0.28 ml) was added thereto. Boc-Leu-ONB [prepared from Boc-Leu-OH.H2 O (0.27 g), HONB (0.22 g) and DCC (0.25 g)] was added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.10 g (91.4%), Melting point: 140°-142° C., Rf1 : 0.34, Rf2 : 0.67 [α]D 28 -0.5° (c=0.84, in DMF)
Elemental analysis: As C66 H74 N8 O14 Calculated: C, 65.88; H, 6.20; N, 9.31 Found: C, 66.00; H, 6.23; N, 9.20
(7) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac
8N-HCl/dioxane was added to Boc-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac (0.96 g) to dissolve it, and the solution was stirred under ice cooling for 10 minutes, followed by concentration. Then, ether was added to the residue to precipitate crystals, which were collected by filtration and dried. The crystals were dissolved in DMF (10 ml) and cooled with ice. Then, TEA (0.22 ml) was added thereto. Boc-D-Thg(2)-OH (0.23 g), HONB (0.13 g) and DCC (0.20 g) were added thereto, followed by stirring for 3 hours. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in AcOEt, and the solution was washed with water, 10% aqueous citric acid and 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 1.06 g (98.7%), Melting point: 162°-164° C., Rf1 : 0.30, Rf2 : 0.69 [α]D 28 +4.4° (c=0.75, in DMF)
Elemental analysis: As C72 H79 N9 O15 S Calculated: C, 64.41; H, 5.93; N, 9.39; S, 2.39 Found: C, 64.36; H, 6.04; N, 9.49; S, 2.16
(8) Production of Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OH
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OPac (0.81 g) was dissolved in 90% aqueous AcOH (20 ml), and Zn powder (1.96 g) was added thereto, followed by stirring for 3 hours. The Zn powder was removed by filtration, and the filtrate was concentrated. AcOEt was added to the residue to dissolve it, and the solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration.
Yield: 0.72 g (98.0%), Melting point: 140°-143° C., Rf1 : 0.22, Rf2 : 0.66 [α]D 28 +5.8° (c=0.93, in DMF)
Elemental analysis: As C64 H73 N9 O14 S Calculated: C, 62.78; H, 6.01; N, 10.30; S, 2.62 Found: C, 62.75; H, 6.14; N, 10.27; S, 2.49
(9) Production of cyclo[-D-Asp-Asn(CH2 CH2 -Ind)-Asp-D-Thg(2)-Leu-D-Trp-]
Boc-D-Thg(2)-Leu-D-Trp-D-Asp(OBzl)-Asn(CH2 CH2 -Ind)-Asp(OBzl)-OH (0.37 g) was dissolved in DCM (10 ml), and the solution was cooled with ice. HONB (0.11 g) and DCC (0.12 g) were added thereto, followed by stirring for 3 hours. Then, the resulting DCU was separated by filtration, followed by concentration, and ether was added to the residue to separate out a precipitate, which was collected by filtration. 8-N HCl/dioxane (10 ml) was added thereto under ice cooling to dissolve the precipitate. The resulting solution was stirred for 10 minutes and concentrated. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. The precipitate was dissolved in DMF (6 ml), and the resulting solution was added dropwise to DMF (54 ml) containing TEA (0.4 ml) for 30 minutes, followed by stirring overnight and concentration. The residue was dissolved in AcOEt, and the solution was washed with 4% aqueous NaHCO3. After washing with water, the solution was dried with Na2 SO4 and concentrated. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration and dried. Of this precipitate, 111 mg was dissolved in DMF (15 ml) and catalytically reduced in a stream of hydrogen using palladium black as a catalyst. The catalyst was removed by filtration, and then the filtrate was concentrated. The resulting residue was dissolved in a small amount of AcOH, and thereafter, water was added thereto to conduct lyophilization. Finally, a part of the lyophilized product was purified by liquid chromatography using a YMC-D-ODS-5 column (2 cm×25 cm) (Y.M.C.) to obtain a desired material. The yield was 5.4 mg (9.5%).
Anal. for amino acids [110° C., hydrolysis for 24 hours; figures in parentheses show theoretical values.]: Asp 3.00(3); Leu 1.39(1) LSIMS (M+H+)=926, (theoretical value)=926 [B]
EXAMPLE
Production of cyclo[-D-Asp-Asn(CH2 CH2 Ind)-AsP-D-Thg(2)-Leu-D-Trp-]
(1) Production of Boc-D-Thg(2)-Leu-OBzl
Boc-Thg(2)-OH.CHA (17.8 g, 50 mmoles) was suspended in a mixed solvent of ethyl acetate (250 ml) and water (250 ml), followed by vigorous stirring. Then, 1N aqueous H2 SO4 (50 ml) was added thereto to dissolve it completely. The ethyl acetate layer was separated and dried with Na2 SO4. The solvent was thereafter removed by evaporation under reduced pressure. DMF (90 ml) was added to the residue to prepare solution (I).
Tos.H-Leu-OBzl (39.4 g, 100 mmoles) was added to a mixed solvent of ethyl acetate (250 ml) and 10% aqueous NaHCO3 (250 ml), followed by vigorous stirring to dissolve it completely. The ethyl acetate layer was separated and dried with Na2 SO4. The solvent was thereafter removed by evaporation under reduced pressure. DMF (90 ml) was added to the residue to prepare solution (II).
Solutions (I) and (II) were combined with each other, and HOBT (13.5 g, 100 mmoles) was added thereto to dissolve it. Then, 30 ml of a solution of DCC (20.6 g, 100 mmoles) in DMF was added dropwise thereto under ice cooling for 10 minutes, followed by stirring for 1 hour. The resulting solution was thereafter stirred overnight at 4° C. The insoluble material was removed by filtration, and the solvent was removed by evaporation. Ethyl acetate and water were added to the residue, and 1N aqueous H2 SO4 (50 ml) was added thereto, followed by extraction with ethyl acetate. The ethyl acetate layer was separated and washed successively with the saturated aqueous solution of NaCl, 4% aqueous NaHCO3 and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed by evaporation. The residue was purified by silica gel column chromatography (6 cm×30 cm, hexane:ethyl acetate=10:1-3:1). Colorless crystals were obtained by crystallization from a petroleum ether solution.
Yield: 14.9 g (87.2%)
Melting point: 71.0°-72.5° C., Rf1: 0.80, Rf2: 0.88 [α]D 25 -46.3° (c=1.02, in DMF)
Elemental analysis: As C24 H32 N2 O5 S Calculated: C, 62.59; H, 7.00; N, 6.08 Found: C, 62.35; H, 7.00; N, 6.10
(2) Production of Boc-D-Thg(2)-Leu-OPac
In 500 ml of methanol was dissolved 16.1 g (35.0 mmoles) of Boc-D-Thg(2)-Leu-OBzl synthesized in (1), and 5 g of charcoal was added thereto, followed by stirring. The charcoal was removed by filtration, and 1 g of palladium black was added to the filtrate. The mixture was stirred in a stream of hydrogen at room temperature for 5 hours. The catalyst was removed by filtration, and the filtrate was concentrated to about 100 ml under reduced pressure. Then, 50 ml of a aqueous solution of Cs2 CO3 (5.70 g, 17.5 mmoles) was added dropwise thereto for 10 minutes, followed by stirring for 30 minutes. The solvent was thereafter removed by evaporation. DMF (100 ml) was added to the residue, and the solvent was removed by evaporation under reduced pressure. This operation was repeated twice. DMF (100 ml) was added to the residue to dissolve it, and 50 ml of a solution of phenacyl bromide (7.18 g, 35.0 mmoles) in DMF was added dropwise thereto under ice cooling for 10 minutes. The resulting mixture was brought to room temperature and then stirred overnight. The solvent was removed by distillation, and ethyl acetate was added to the residue, followed by extraction with ethyl acetate. The ethyl acetate layer was separated and washed successively with 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO3 and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed. Colorless crystals were obtained by crystallization from an ether-petroleum ether.
Yield: 14.9 (87.2%)
Melting point: 119.0°-120.0° C., Rf1: 0.79, Rf2: 0.91 [α]D 25 -50.2° (c=1.05, in DMF)
Elemental analysis: As C25 H32 N2 O6 S Calculated: C, 61.46; H, 6.60; N, 5.73 Found: C, 61.43; H, 6.63; N, 5.85
(3) Production of Boc-Asp(OBzl)-D-Thg(2)-Leu-OPac
In 30 ml of dioxane was dissolved 14.7 g (30.0 mmoles) of Boc-D-Thg(2)-Leu-OPac synthesized in (2), and 10N-HCl/dioxane (50 ml) was added thereto under ice cooling, followed by stirring for 15 minutes. The solvent was removed by evaporation under reduced pressure, and ether was added to the residue. The resulting precipitate was collected by filtration and dried. The precipitate was dissolved in DMF (160 ml) and the solution was cooled with ice. Then, diisopropylethylamine (5.30 ml, 30.36 mmoles) was added thereto. Boc-Asp(OBzl)-ONB [prepared from Boc-Asp(OBzl)-OH (9.68 g, 30 mmoles), HONB (5.91 g, 33.0 mmoles) and DCC (6.81 g, 33.0 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration. The residue was dissolved in ethyl acetate, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO3 and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed by evaporation. Ether-petroleum ether was added to the residue to obtain a precipitate.
Yield: 20.31 g (97.6%)
Melting point: 67.0°-68.5° C., Rf1: 0.61, Rf2: 0.83 [α]D 25 -52.0° (c=1.03, in DMF)
Elemental analysis: As C36 H43 N3 O9 S Calculated: C, 62.32; H, 6.25; N, 6.06 Found: C, 62.34; H, 6.36; N, 6.20
(4) Production of Boc-Asn(NHCH2 CH2 Ind)-AsP(OBzl)-D-Thg(2)-Leu-OPac
In 30 ml of dioxane was dissolved 20.1 g (29.0 mmoles) of Boc-Asp(OBzl)-D-Thg(2)-Leu-OPac synthesized in (3), and 10N-HCl/dioxane (150 ml) was added thereto under ice cooling, followed by stirring for 15 minutes. The solvent was removed by evaporation under reduced pressure, and ether was added to the residue. The resulting precipitate was collected by filtration and dried. The precipitate was dissolved in DMF (240 ml) and the solution was cooled with ice. Then, diisopropylethylamine (5.05 ml, 29.0 mmoles) was added thereto. Boc-Asn(CH2 CH2 -Ind)-ONB [prepared from Boc-Asn(NHCH2 CH2 ind)-OH {prepared from Boc-Asn(NHCH2 CH2 Ind)-OH.CHA (14.5 g, 30.45 mmoles)}, HONB (5.72 g, 31.9 mmoles) and DCC (6.58 g, 31.9 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. Ethyl acetate-ether (1:1) was added to the residue to obtain a precipitate.
Yield: 26.68 g (96.7%)
Melting point: 178.0°-180.5° C., Rf1: 0.38, Rf2: 0.77 [α]D 25 -44.8° (c=1.03, in DMF)
Elemental analysis: As C50 H58 N6 O11 S Calculated: C, 63.14; H, 6.15; N, 8.84 Found: C, 62.85; H, 6.11; N, 8.80
(5) Production of Boc-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OPac
In 25 ml of dioxane was dissolved 24.7 g (26.0 mmoles) of Boc-Asn(CH2 CH2 -Ind)-Asp(OBzl)-D-Thg(2)-Leu-OPac synthesized in (4), and 10N-HCl/dioxane (130 ml) was added thereto under ice cooling, followed by stirring for 15 minutes. The solvent was removed by evaporation under reduced pressure, and ether was added to the residue. The resulting precipitate was collected by filtration and dried. The precipitate was dissolved in DMF (200 ml), and diisopropylethylamine (4.53 ml, 26.0 mmoles) was added thereto under ice cooling. Boc-D-Asp(OBzl)-ONB [prepared from Boc-D-Asp(OBzl)-OH (8.82 g, 27.3 mmoles), HONB (5.12 g, 28.6 mmoles) and DCC (5.90 g, 28.6 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. The residue was dissolved in ethyl acetate, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO3 and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed by evaporation. Ethyl acetate-ether was added to the residue to obtain a precipitate.
Yield: 25.82 g (85.9%)
Melting point: 148.0°-150.0° C., Rf1: 0.54 Rf2: 0.78 [α]D 25 -38.9° (c=1.04, in DMF)
Elemental analysis: As C61 H69 N7 O14 S Calculated: C, 63.36; H, 6.01; N, 8.48 Found: C, 63.15; H, 6.00; N, 8.45
(6) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OPac
In 22 ml of dioxane was added 25.44 g (22.0 mmoles) of Boc-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OPac synthesized in (5), and 10N-HCl/dioxane (110 ml) was added thereto under ice cooling, followed by stirring for 15 minutes. The solvent was removed by evaporation under reduced pressure, and ether was added to the residue. The resulting precipitate was collected by filtration and dried. The precipitate was dissolved in DMF (200 ml), and the solution was cooled with ice. Then, diisopropylethylamine (3.83 ml, 22.0 mmoles) was added thereto. Boc-D-Trp-ONB [prepared from Boc-D-Trp-OH (6.70 g, 22.0 mmoles), HONB (4.34 g, 24.2 mmoles) and DCC (5.00 g, 24.2 mmoles)] was further added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. The residue was dissolved in chloroform, and the solution was washed with water, 10% aqueous citric acid, the saturated aqueous solution of NaCl, the saturated aqueous solution of NaHCO3 and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed by evaporation. The residue was purified by silica gel column chromatography (9.5 cm×50 cm, 0.5% methanol-chloroform). Ether-petroleum ether was added to the purified product to obtain a precipitate.
Yield: 20.10 g (68.0%)
Melting point: 172.0°-173.5° C., Rf1: 0.52, Rf2: 0.77 [α]D 25 -24.1° (c=1.05, in DMF)
Elemental analysis: As C72 H79 N9 O15 S Calculated: C, 64.41; H, 5.93; N, 9.39 Found: C, 64.35; H, 5.99; N, 9.22
(7) Production of Boc-D-Trp-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OH
In 500 ml of a 90% aqueous solution of acetic acid was dissolved 6.71 g (5.00 mmoles) of Boc-D-Trp-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OPac synthesized in (6), and 16.33 g (250.0 mmoles) of zinc powder was added thereto, followed by stirring for 1 hour. The zinc powder was separated by filtration, and the filtrate was concentrated. The residue was dissolved in ethyl acetate, and the solution was washed with 10% aqueous citric acid and the saturated aqueous solution of NaCl. After drying with Na2 SO4, the solvent was removed by evaporation. Ether was added to the residue to obtain a precipitate.
Yield: 6.00 g (98.0%)
Melting point: 120.0°-122.0° C. Rf1: 0.00, Rf2: 0.67 [α]D 25 -18.8° (c=1.03, in DMF)
Elemental analysis: As C64 H73 N9 O14 S Calculated: C, 62.78; H, 6.01; N, 10.30 Found: C, 62.66; H, 5.96; N, 10.06
(8) Production of cyclo[-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-D-Trp-]
In 80 ml of DMF was dissolved 5.82 g (4.75 mmoles) of Boc-D-Trp-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-OH synthesized in (7), and the solution was cooled with ice. Then, HONB (1.70 g, 9.50 mmoles) and DCC (1.96 g, 9.50 mmoles) were added thereto, followed by stirring overnight. The resulting insoluble material was separated by filtration, followed by concentration of the filtrate to obtain the residue. Then, ether-petroleum ether was added to the residue to separate out a precipitate, which was collected by filtration. The precipitate was dissolved in dioxane (5 ml), and 10N- HCl/dioxane (50 ml) was added thereto under ice cooling, followed by stirring for 5 minutes. After concentration of the filtrate to obtain the residue, ether was added to the residue. The resulting precipitate was collected by filtration and dried. The precipitate was dissolved in DMF (100 ml). The solution was added dropwise to 900 ml of DMF containing diisopropylethylamine (8.27 ml, 47.5 mmoles) for 30 minutes, followed by stirring overnight. The solvent was removed by evaporation, and distilled water was added to the residue. The resulting precipitate was collected by filtration. The precipitate was dissolved in DMF, followed by concentration of the filtrate to obtain the residue. Then, ether was added to the residue to separate out a precipitate, which was collected by filtration, washed with acetonitrile and dried.
Yield: 4.75 g (90.4%)
(9) Production of cyclo[-D-Asp-Asn(NHCH2 CH2 Ind)-Asp-D-Thg(2)-Leu-D-Trp-]
In 100 ml of DMF was dissolved 2.00 g (1.81 mmoles) of cyclo[-D-Asp(OBzl)-Asn(NHCH2 CH2 Ind)-Asp(OBzl)-D-Thg(2)-Leu-D-Trp-] synthesized in (8), and 1 g of charcoal was added thereto, followed by stirring. The charcoal was removed by filtration, and 1 g of palladium black was added to the filtrate. The mixture was stirred in a stream of hydrogen at room temperature for 6 hours. In addition, 1 g of palladium black was added, and the mixture was stirred in a stream of hydrogen at room temperature for 6 hours. The catalyst was removed by filtration, and the solvent was removed by evaporation under reduced pressure. Then, ether was added to obtain a precipitate.
Yield: 1.68 g (quant.)
Of this precipitate, 1.50 g was purified by reversed phase liquid chromatography [column: YMC-Pack R & D D-ODS-5B (3 cm×25 cm), solvent: 30%-40% acetonitrile (30 minutes)/H2 O (0.1% TFA)].
Yield: 1.11 g LSIMS (M+H+)=926, (theoretical value)=926
(10) Production of cyclo[-D-Asp-Asn(NHCH2 CH2 Ind)-Asp-D-Thg(2)-Leu-D-Trp-].2Na
In 60 ml of acetonitrile was suspended 3.00 g (3.24 mmoles) of cyclo[-D-Asp-Asn(NHCH2 CH2 Ind)-Asp-D-Thg(2)-Leu-D-Trp-] synthesized in (9), and the suspension was added dropwise to 240 ml of an aqueous solution of sodium carbonate (343.4 mg, 3.24 mmoles). After stirring at room temperature for 15 minutes, the pH was adjusted to 7.0 with a 0.1M aqueous solution of sodium carbonate, followed by concentration under reduced pressure. The resulting product was dissolved in 100 ml of distilled water and subjected to lyophilization.
Yield: 2.80 g
EXAMPLES 15-52, 57-78, 83-87 and 91-96
In accordance with the processes of Examples 1-14 (A), the processes of Examples 53-56 and 88-90 (B) or the processes of Examples 79-82 (C), the following compounds were synthesized:
__________________________________________________________________________
Example                                                                   
No.  Compound                              Process                        
__________________________________________________________________________
15   Cyclo[--D--Asp--D--Ala--Asp--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 714, (theoretical value) = 714                  
16   Cyclo[--D--Asp--Asp--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 758, (theoretical value) = 758                  
17   Cyclo[--D--Asp--Val--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 742, (theoretical value) = 742                  
18   Cyclo[--D--Asp--Leu--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 756, (theoretical value) = 756                  
19   Cyclo[--D--Asp--Phe--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 790, (theoretical value) = 790                  
20   Cyclo[--D--Asp--Ser(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 820, (theoretical value) = 820                  
21   Cyclo[--D--Asp--Thr(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 834, (theoretical value) = 834                  
22   Cyclo[--D--Asp--Trp(For)--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 857, (theoretical value) = 857                  
23   Cyclo[--D--Asp--Nal(1)--Asp--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 840, (theoretical value) = 840                  
24   Cyclo[--D--Asp--D--Pro--Asp--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 740, (theoretical value) = 740                  
25   Cyclo[--D--Asp--Azc--Asp--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 725, (theoretical value) = 725                  
26   Cyclo[--D--Asp--Pip--Asp--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 753, (theoretical value) = 753                  
27   Cyclo[--D--Asp--D--Asp--Ala--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 714, (theoretical value) = 714                  
28   Cyclo[--D--Asp--D--Glu--Ala--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 728, (theoretical value) = 728                  
29   Cyclo[--D--Asp--Asp--D--Ala--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 714, (theoretical value) = 714                  
30   Cyclo[--D--Asp--Asp--Pro--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 740, (theoretical value) = 740                  
31   Cyclo[--D--Asp--Asp--D--Pro--D--Leu--Leu--D--Trp--]                  
                                           (A)                            
     LSIMS(M + H.sup.+) = 740, (theoretical value) = 740                  
32   Cyclo[--D--Asp--Asp--Leu--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 756, (theoretical value) = 756                  
33   Cyclo[--D--Asp--Asp--Trp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 829, (theoretical value) = 829                  
34   Cyclo[--D--Asp--Trp--Glu--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 844, (theoretical value) = 844                  
35   Cyclo[--D--Asp--Trp--Leu--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 828, (theoretical value) = 828                  
36   Cyclo[--D--Asp--Trp--Pro--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 811, (theoretical value) = 811                  
37   Cyclo[--D--Asp--Trp--Ser--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 801, (theoretical value) = 801                  
38   Cyclo[--D--Asp--Trp--Ser(Bzl)--D--Leu--Leu--D--Trp--]                
                                           (C)                            
     LSIMS(M + H.sup.+) = 892, (theoretical value) = 892                  
39   Cyclo[--D--Asp--Ala--Asp--D--tLeu--Leu--D--Trp--]                    
                                           (A)                            
     LSIMS(M + H.sup.+) = 714, (theoretical value) = 714                  
40   Cyclo[--D--Glu--Ala--Gly--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 670, (theoretical value) = 670                  
41   Cyclo[--D--Glu--Ala--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 728, (theoretical value) = 728                  
42   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(For)--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 857, (theoretical value) = 857                  
43   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(Ac)--]                 
                                           (A)                            
     LSIMS(M + H.sup.+) = 871, (theoretical value) = 871                  
44   Cyclo[--D--Asp--Trp--Asp--Acpe--Leu--D--Trp--]                       
                                           (B)                            
     LSIMS(M + H.sup.+) = 827, (theoretical value) = 827                  
45   Cyclo[--D--Asp--Trp--Asp--D--Phg--Leu--D--Trp--]                     
                                           (B)                            
     LSIMS(M + H.sup.+) = 849, (theoretical value) = 849                  
46   Cyclo[--D--Asp--Sar--Asp--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 714, (theoretical value) = 714                  
47   Cyclo[--D--Asp--N--MeLeu--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 770, (theoretical value) = 770                  
48   Cyclo[--D--Asp--N--MePhe--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 804, (theoretical value) = 804                  
49   Cyclo[--D--Asp--Trp--Asp--D--Thg(3)--Leu--D--Trp--]                  
                                           (B)                            
     LSIMS(M + H.sup.+) = 855, (theoretical value) = 855                  
50   Cyclo[--D--Asp--Trp--Asp--D--Thi--Leu--D--Trp--]                     
                                           (B)                            
     LSIMS(M + H.sup.+) = 869, (theoretical value) = 869                  
51   Cyclo[--D--Asp--Trp--Asp--D--aIle--Leu--D--Trp--]                    
                                           (B)                            
     LSIMS(M + H.sup.+) = 829, (theoretical value) = 829                  
52   Cyclo[--D--Asp--Trp--Asp--D--Val--Leu--D--Trp--]                     
                                           (B)                            
     LSIMS(M + H.sup.+) = 815, (theoretical value) = 815                  
57   Cyclo[--D--Asp--Ala--Asp--D--Leu--Phe--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 748, (theoretical value) = 748                  
58   Cyclo[--D--Asp--Ala--Asp--D--Leu--Trp--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 787, (theoretical value) = 787                  
59   Cyclo[--D--Glu--Gly--Ala--D--Leu--Leu--D--Trp--]                     
                                           (A)                            
     LSIMS(M + H.sup.+) = 670, (theoretical value) = 670                  
60   Cyclo[--D--Asp--Trp--Asp--D--Phe--Leu--D--Trp--]                     
                                           (B)                            
     LSIMS(M + H.sup.+) = 863, (theoretical value) = 863                  
61   Cyclo[--D--Asp--Trp--Asp--Achx--Leu--D--Trp--]                       
                                           (B)                            
     LSIMS(M + H.sup.+) = 841, (theoretical value) = 841                  
62   Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--]        
                                           (C)                            
     LSIMS(M + H.sup.+) = 861, (theoretical value) = 861                  
63   Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--
     ]                                     (C)                            
     LSIMS(M + H.sup.+) = 875, (theoretical value) = 875                  
64   Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Leu--Leu--D--Tr
     p--]                                  (C)                            
     LSIMS(M + H.sup.+) = 914, (theoretical value) = 914                  
65   Cyclo[--D--Asp--Arg(Tos)--Asp--D--Leu--Leu--D--Trp--]                
                                           (C)                            
     LSIMS(M + H.sup.+) = 953, (theoretical value) = 953                  
66   Cyclo[--D--Asp--Lys(Mtr)--Asp--D--Leu--Leu--D--Trp--]                
                                           (C)                            
     LSIMS(M + H.sup.+) = 983, (theoretical value) = 983                  
67   Cyclo[--D--Asp--N--MeTrp--Asp--D--Leu--Leu--D--Trp--]                
                                           (A)                            
     LSIMS(M + H.sup.+) = 843, (theoretical value) = 843                  
68   Cyclo[--D--Asp--Asn(Me.CH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Tr
     p--]                                  (C)                            
     LSIMS(M + H.sup.+) = 875, (theoretical value) = 875                  
69   Cyclo[--D--Asp--Asn(CH.sub.2 CHMePh)--Asp--D--Leu--Leu--D--Trp--]    
                                           (C)                            
     LSIMS(M + H.sup.+) = 875, (theoretical value) = 875                  
70   Cyclo[--D--Asp--Asp(R1)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 902, (theoretical value) = 902                  
71   Cyclo[--D--Asp--Asp(R2)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 901, (theoretical value) = 901                  
72   Cyclo[--D--Asp--Asp(R3)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 859, (theoretical value) = 859                  
73   Cyclo[--D--Asp--Asp(R4)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 873, (theoretical value) = 873                  
74   Cyclo[--D--Asp--Asp(R5)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 887, (theoretical value) = 887                  
75   Cyclo[--D--Asp--Asp(R6)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 868, (theoretical value) = 868                  
76   Cyclo[--D--Asp--Glu(R3)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 873, (theoretical value) = 873                  
77   Cyclo[--D--Asp--Glu(R4)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 887, (theoretical value) = 887                  
78   Cyclo[--D--Asp--Glu(R5)--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 901, (theoretical value) = 901                  
83   Cyclo[--D--Asp--His--Asp--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 780, (theoretical value) = 780                  
84   Cyclo[--D--Asp--His(Bom)--Asp--D--Leu--Leu--D--Trp--]                
                                           (C)                            
     LSIMS(M + H.sup.+) = 900, (theoretical value) = 900                  
85   Cyclo[--D--Asp--His(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           (C)                            
     LSIMS(M + H.sup.+) = 870, (theoretical value) = 870                  
86   Cyclo[--D--Asp--D,L-Tic--Asp--D--Leu--Leu--D--Trp--]                 
                                           (C)                            
     LSIMS(M + H.sup.+) = 802, (theoretical value) = 802                  
87   Cyclo[--D--Asp--Tpr--Asp--D--Leu--Leu--D--Trp--]                     
                                           (C)                            
     LSIMS(M + H.sup.+) = 758, (theoretical value) = 758                  
91   Cyclo[--D--Asp--Asp(Trp--NHEt)--Asp--D--Leu--Leu--D--Trp--]          
                                           (C)                            
     LSIMS(M + H.sup.+) = 971, (theoretical value) = 971                  
92   Cyclo[--D--Asp--Asp(Trp--NHBzl)--Asp--D--Leu--Leu--D--Trp--]         
                                           (C)                            
     LSIMS(M + H.sup.+) = 1033, (theoretical value) = 1033                
93   Cyclo[--D--Asp--Asp(D--Trp--NHBzl)--Asp--D--Leu--Leu--D--Trp--]      
                                           (C)                            
     LSIMS(M + H.sup.+) = 1033, (theoretical value) = 1033                
94   Cyclo[--D--Asp--Asp(Trp--NHCH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D
     --Trp--]                              (C)                            
     LSIMS(M + H.sup.+) = 1047, (theoretical value) = 1047                
95   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(Me)--]                 
                                           (A)                            
     LSIMS(M + H.sup.+) = 843, (theoretical value) = 843                  
96   Cyclo[--D--Asp--Asp(R1)--Asp--D--Thg(2)--Leu--D--Trp--]              
                                           (A)                            
     LSIMS(M + H.sup.+) = 928, (theoretical value) = 928                  
__________________________________________________________________________
EXAMPLES 97-203
In accordance with any one of the processes (A), (B) and (C) mentioned above, the following compounds can be synthesized:
__________________________________________________________________________
Example                                                                   
No.  Compound                                                             
__________________________________________________________________________
 97  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Phg--Leu--D--Tr
     p--]                                                                 
 98  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(3)--Leu--D-
     -Trp--]                                                              
 99  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--Acbu--Leu--D--Trp-
     -]                                                                   
100  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--Acpe--Leu--D--Trp-
     -]                                                                   
101  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--Achx--Leu--D--Trp-
     -]                                                                   
102  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--Achp--Leu--D--Trp-
     -]                                                                   
103  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp(Me)--]                                                          
104  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp(For)--]                                                         
105  Cyclo[--D--Cta--Trp--Asp--D--Val--Leu--D--Trp--]                     
106  Cyclo[--D--Cta--Trp--Asp--D--Leu--Leu--D--Trp--]                     
107  Cyclo[--D--Cta--Trp--Asp--D--Thg(2)--Leu--D--Trp--]                  
108  Cyclo[--D--Cta--Trp--Asp--D--Thg(3)--Leu--D--Trp--]                  
109  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Val--Leu--D--Tr
     p--]                                                                 
110  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Leu--Leu--D--Tr
     p--]                                                                 
111  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp--]                                                              
112  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(3)--Leu--D-
     -Trp--]                                                              
113  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp(Me)--]                                                          
114  Cyclo[--D--Cta--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp(For)--]                                                         
115  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Trp--]     
116  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Phg--Leu--D--Trp--]        
117  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--]        
118  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Val--Leu--D--Trp--]        
119  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--aIle--Leu--D--Trp--]       
120  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--tLeu--Leu--D--Trp--]       
121  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Thg(2)--Leu--D--Trp(Me)--] 
122  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Trp(Me)--] 
123  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Thg(2)--Leu--D--Trp(For)--]
124  Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Trp(For)--]
125  Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Thg(2)--Leu--D--Tr
     p--]                                                                 
126  Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Tr
     p--]                                                                 
127  Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp--]                                                              
128  Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(3)--Leu--D-
     -Trp--]                                                              
129  Cyclo[--D--Cta--Gln(CH.sub.2 Ph)--Asp--D--Thg(2)--Leu--D--Trp--]     
130  Cyclo[--D--Cta--Gln(CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Trp--]     
131  Cyclo[--D--Cta--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Thg(2)--Leu--D--Tr
     p--]                                                                 
132  Cyclo[--D--Cta--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Thg(3)--Leu--D--Tr
     p--]                                                                 
133  Cyclo[--D--Cta--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(2)--Leu--D-
     -Trp--]                                                              
134  Cyclo[--D--Cta--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Thg(3)--Leu--D-
     -Trp--]                                                              
135  Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Val--Leu--D--Tr
     p--]                                                                 
136  Cyclo[--D--Asp--Asp(R7)--Asp--D--Thg(2)--Leu--D--Trp--]              
137  Cyclo[--D--Asp--Asp(R8)--Asp--D--Thg(2)--Leu--D--Trp--]              
138  Cyclo[--D--Asp--Asp(R9)--Asp--D--Thg(2)--Leu--D--Trp--]              
139  Cyclo[--D--Asp--Asp(R10)--Asp--D--Thg(2)--Leu--D--Trp--]             
140  Cyclo[--D--Asp--Asp(R11)--Asp--D--Thg(2)--Leu--D--Trp--]             
141  Cyclo[--D--Asp--Asp(R12)--Asp--D--Thg(2)--Leu--D--Trp--]             
142  Cyclo[--D--Asp--Asp(R13)--Asp--D--Thg(2)--Leu--D--Trp--]             
143  Cyclo[--D--Asp--Asp(R14)--Asp--D--Thg(2)--Leu--D--Trp--]             
144  Cyclo[--D--Asp--Asp(R15)--Asp--D--Thg(2)--Leu--D--Trp--]             
145  Cyclo[--D--Asp--Asp(R16)--Asp--D--Thg(2)--Leu--D--Trp--]             
146  Cyclo[--D--Cta--Asp(R1)--Asp--D--Thg(2)--Leu--D--Trp--]              
147  Cyclo[--D--Cta--Asp(R7)--Asp--D--Thg(2)--Leu--D--Trp--]              
148  Cyclo[--D--Cta--Asp(R8)--Asp--D--Thg(2)--Leu--D--Trp--]              
149  Cyclo[--D--Cta--Asp(R9)--Asp--D--Thg(2)--Leu--D--Trp--]              
150  Cyclo[--D--Cta--Asp(R10)--Asp--D--Thg(2)--Leu--D--Trp--]             
151  Cyclo[--D--Cta--Asp(R11)--Asp--D--Thg(2)--Leu--D--Trp--]             
152  Cyclo[--D--Cta--Asp(R12)--Asp--D--Thg(2)--Leu--D--Trp--]             
153  Cyclo[--D--Cta--Asp(R13)--Asp--D--Thg(2)--Leu--D--Trp--]             
154  Cyclo[--D--Cta--Asp(R14)--Asp--D--Thg(2)--Leu--D--Trp--]             
155  Cyclo[--D--Cta--Asp(R15)--Asp--D--Thg(2)--Leu--D--Trp--]             
156  Cyclo[--D--Cta--Asp(R16)--Asp--D--Thg(2)--Leu--D--Trp--]             
157  Cyclo[--D--Asp--Asp(R1)--Asp--D--Cpg--Leu--D--Trp--]                 
158  Cyclo[--D--Asp--Asp(R7)--Asp--D--Cpg--Leu--D--Trp--]                 
159  Cyclo[--D--Asp--Asp(R8)--Asp--D--Cpg--Leu--D--Trp--]                 
160  Cyclo[--D--Asp--Asp(R9)--Asp--D--Cpg--Leu--D--Trp--]                 
161  Cyclo[--D--Asp--Asp(R10)--Asp--D--Cpg--Leu--D--Trp--]                
162  Cyclo[--D--Asp--Asp(R11)--Asp--D--Cpg--Leu--D--Trp--]                
163  Cyclo[--D--Asp--Asp(R12)--Asp--D--Cpg--Leu--D--Trp--]                
164  Cyclo[--D--Asp--Asp(R13)--Asp--D--Cpg--Leu--D--Trp--]                
165  Cyclo[--D--Asp--Asp(R14)--Asp--D--Cpg--Leu--D--Trp--]                
166  Cyclo[--D--Asp--Asp(R15)--Asp--D--Cpg--Leu--D--Trp--]                
167  Cyclo[--D--Asp--Asp(R16)--Asp--D--Cpg--Leu--D--Trp--]                
168  Cyclo[--D--Cta--Asp(R1)--Asp--D--Cpg--Leu--D--Trp--]                 
169  Cyclo[--D--Cta--Asp(R7)--Asp--D--Cpg--Leu--D--Trp--]                 
170  Cyclo[--D--Cta--Asp(R8)--Asp--D--Cpg--Leu--D--Trp--]                 
171  Cyclo[--D--Cta--Asp(R9)--Asp--D--Cpg--Leu--D--Trp--]                 
172  Cyclo[--D--Cta--Asp(R10)--Asp--D--Cpg--Leu--D--Trp--]                
173  Cyclo[--D--Cta--Asp(R11)--Asp--D--Cpg--Leu--D--Trp--]                
174  Cyclo[--D--Cta--Asp(R12)--Asp--D--Cpg--Leu--D--Trp--]                
175  Cyclo[--D--Cta--Asp(R13)--Asp--D--Cpg--Leu--D--Trp--]                
176  Cyclo[--D--Cta--Asp(R14)--Asp--D--Cpg--Leu--D--Trp--]                
177  Cyclo[--D--Cta--Asp(R15)--Asp--D--Cpg--Leu--D--Trp--]                
178  Cyclo[--D--Cta--Asp(R16)--Asp--D--Cpg--Leu--D--Trp--]                
179  Cyclo[--D--Asp--Asp(R7)--Asp--D--Leu--Leu--D--Trp--]                 
180  Cyclo[--D--Asp--Asp(R8)--Asp--D--Leu--Leu--D--Trp--]                 
181  Cyclo[--D--Asp--Asp(R9)--Asp--D--Leu--Leu--D--Trp--]                 
182  Cyclo[--D--Asp--Asp(R10)--Asp--D--Leu--Leu--D--Trp--]                
183  Cyclo[--D--Asp--Asp(R11)--Asp--D--Leu--Leu--D--Trp--]                
184  Cyclo[--D--Asp--Asp(R12)--Asp--D--Leu--Leu--D--Trp--]                
185  Cyclo[--D--Asp--Asp(R13)--Asp--D--Leu--Leu--D--Trp--]                
186  Cyclo[--D--Asp--Asp(R14)--Asp--D--Leu--Leu--D--Trp--]                
187  Cyclo[--D--Asp--Asp(R15)--Asp--D--Leu--Leu--D--Trp--]                
188  Cyclo[--D--Asp--Asp(R16)--Asp--D--Leu--Leu--D--Trp--]                
189  Cyclo[--D--Cta--Asp(R1)--Asp--D--Leu--Leu--D--Trp--]                 
190  Cyclo[--D--Cta--Asp(R7)--Asp--D--Leu--Leu--D--Trp--]                 
191  Cyclo[--D--Cta--Asp(R8)--Asp--D--Leu--Leu--D--Trp--]                 
192  Cyclo[--D--Cta--Asp(R9)--Asp--D--Leu--Leu--D--Trp--]                 
193  Cyclo[--D--Cta--Asp(R10)--Asp--D--Leu--Leu--D--Trp--]                
194  Cyclo[--D--Cta--Asp(R11)--Asp--D--Leu--Leu--D--Trp--]                
195  Cyclo[--D--Cta--Asp(R12)--Asp--D--Leu--Leu--D--Trp--]                
196  Cyclo[--D--Cta--Asp(R13)--Asp--D--Leu--Leu--D--Trp--]                
197  Cyclo[--D--Cta--Asp(R14)--Asp--D--Leu--Leu--D--Trp--]                
198  Cyclo[--D--Cta--Asp(R15)--Asp--D--Leu--Leu--D--Trp--]                
199  Cyclo[--D--Cta--Asp(R16)--Asp--D--Leu--Leu--D--Trp--]                
200  Cyclo[--D--Asp--Asp(R1)--Asp--D--Thi--Leu--D--Trp--]                 
201  Cyclo[--D--Asp--Asp(R1)--Asp--D--Phe--Leu--D--Trp--]                 
202  Cyclo[--D--Cta--Asp(R1)--Asp--D--Thi--Leu--D--Trp--]                 
203  Cyclo[--D--Cta--Asp(R1)--Asp--D--Phe--Leu--D--Trp--]                 
__________________________________________________________________________
In the formulae, R1 to R16 represent the following groups: ##STR3## Experimental Example 1
Assay of Affinity for Receptor (1) . . . Binding Activity on ETA Receptor
A membrane fraction prepared from the porcine heart was diluted to 0.15 mg/ml by using a buffer solution for assay, and 100 μl of the resulting suspension of the membrane fraction was poured into each assay tube to use for assay. To this suspension of the membrane fraction was added 2 μl of 5 nM 125 I-labeled endothelin-1 solution. Further, 3 μl of a test peptide solution was added thereto, followed by incubation at a temperature of 25° C. for 1 hour. Then, the resulting suspension was diluted with 900 μl of the buffer solution for assay cooled with ice, and thereafter separated into a supernatant and a precipitate by centrifugation at 12,000×g for 10 minutes. Cell membranes and an endothelin receptor A (ETA) embedded therein were contained in the precipitate, and radioactive iodine-labeled endothelin combined with the receptor was also recovered in the precipitate. Accordingly, the amount of radioactive iodine-labeled endothelin combined with the endothelin receptor A (ETA) was determined by measuring the amount of radioactive iodine contained in the precipitate with a gamma-ray counter. Results are as shown in Table 1 given below. The cyclic pentapeptide described in Japanese Patent Application No. 2-413828/1990, cyclo[-D-Glu-Ala-D-aIle-Leu-D-Trp-], was used as a control compound. The numerical value of ETA shown in Table 1 is the value of specific activity, taking the binding activity of this cyclic pentapeptide on the receptor A as 1.0. The binding activity (IC50) of this cyclic pentapeptide on the ETA receptor is 2×10-6 M.
Experimental Example 2
Assay of Affinity for Receptor (2) . . . Binding Activity on ETB Receptor *1
A membrane fraction prepared from the bovine brain was diluted to 0.15 mg/ml by using a buffer solution for assay, and 100 μl of the resulting suspension of the membrane fraction was poured into each assay tube to use for assay. To this suspension of the membrane fraction was added 2 μl of 5 nM 125 I labeled endothelin-1 solution. Further, 3 μl of a test peptide solution was added thereto, followed by incubation at a temperature of 25° C. for 1 hour. Then, the resulting suspension was diluted with 900 μl of the buffer solution for assay cooled with ice, and thereafter separated into a supernatant and a precipitate by centrifugation at 12,000×g for 10 minutes. Cell membranes and an endothelin receptor B (ETB) embedded therein were contained in the precipitate, and radioactive iodine-labeled endothelin bound to the receptor was also recovered in the precipitate. Accordingly, the amount of radioactive iodine-labeled endothelin bound to the endothelin receptor B (ETB) was determined by measuring the amount of radioactive iodine contained in the precipitate with a gamma-ray counter. Results are as shown in Table 1 given below. The numerical value of ETB shown in Table 1 is the value of specific activity, taking the binding activity of the compound of Example 8 on the receptor B as 100. The binding activity (IC50) of the compound of Example 8 on the ETB receptor is 3×10-6 M. According to the same assay, the value of specific activity of the pentapeptide described in European Patent Publication No. 436,189, cyclo[-D-Asp-Pro-D-val-Leu-D-Trp-], was less than 5, and that of the above-mentioned cyclic pentapeptide described in Japanese Patent Application No. 2-413328/1990, cyclo[-D-Glu-Ala-D-aIle-Leu-D-Trp-], was less than 1.
Experimental Example 2'
ETB Radio Receptor Assay *2
In the endothelin radio receptor assay, guinea pigs' kidneys were used. Guinea pigs (Std Hartrey, male 250 g, Japan SLC Ltd.) were made to have a cerebral concussion and sacrificed by bleeding from carotid arteries to pick up the kidneys and removed fat therefrom to prepare the kidneys. The obtained kidneys were sliced and homogenized by politron homogenizer in 20 ml of 50 mM Tris-HCl buffer [pH 7.4; 20 mM NaHCO3, 0.1 mM PMSF (Phenylmethylsulfonyl Fluoride), 1 mM EDTA (Ethylenediaminetetraacetic acid)] per one kidney. The homogenized kidney was applied to a centrifugation at 1,000×g for 15 minutes and the supernatant was further applied to a centrifugation for 20 minutes at 30,000×g. The resulting precipitate was twice washed with 50 mM Tris-HCl buffer (pH 7.4) containing 0.1 mM PMSF, 1 mM EDTA. The resultant was stored at -80 ° C. as a crude receptor membrane fraction and was used as the suspension in the following buffer when necessary.
740 Bq of 125 I-endothelin-1 (81.4 TBq/mmol, Du Pont, USA) as a radio ligand, the crude membrane fraction (2.1 μg protein) and samples were added to the following buffer. The reaction was performed at 37° C., for 90 minutes in 0.2 ml of the buffer [50 mM Tris-HCl buffer (pH 7.4) containing 0.1 mM PMSF, 1 mM EDTA, 0.2% bovine serum albumin].
The reaction was stopped by fast filtration on a glass filter (GF/B, Wattman, USA) by Cell Harvestor (290 PHD, Cambridge-Technology, Great Britain), and the filter was three times washed with 50 mM Tris-HCl buffer (pH 7.4). Radio activity remained on the filter was assayed by a gamma counter.
The results are shown in Table 1.
Experimental Example 3
Assay of Affinity for Receptor (3) . . . Binding Inhibiting Activity on NK2 Receptor
The method of Paul L. M. Van Giersbergen et al. [Proc. Natl. Acad. Sci. U.S.A., 88, 1661 (1991) was modified for this assay. The membrane fraction containing the receptor was prepared from the inner wall of the bovine third stomach (purchased from Kyoto Chuo Chikusan Fukuseibutsu Oroshi Kyoukai).
The inner wall of the bovine third stomach stored at -80° C. was cut to 1 cm×1 cm or less, and disrupted in 3 liters/kg of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 120 mM sodium chloride, 5 mM potassium chloride, 0.02% BSA and 5% sucrose, using a polytron homogenizer (Kinematika, Germany). Then, the disrupted product was centrifuged at 1,000×g for 10 minutes. The supernatant was further centrifuged at 45,000×g for 20 minutes. The precipitate was suspended in 200 ml of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 300 mM potassium chloride, 10 mM ethylenediaminetetraacetic acid, 0.1 mM phenylmethylsulfonium fluoride and 0.02% BSA, and gently stirred under ice cooling for 60 minutes. The suspension was centrifuged at 45,000×g for 20 minutes. The precipitate was washed with 200 ml of 50 mM Tris-HCl buffer (pH 7.4), and stored in the frozen state at -40° C. as a receptor sample.
This sample was suspended in a reaction buffer solution [50 mM Tris-HCl buffer (pH 7.4), 0.02% bovine serum albumin and 4 mM manganese chloride] so as to give a protein concentration of 0.7 mg/ml, and 100 μl thereof was used for reaction. A test sample and 125 I-NKA (0.61 KBq, 125 I-neurokinin A, 81.4 TBq/mmol, Du Pont/NEN Research Products, U.S.A.) were also added, and reacted in 0.2 ml of the reaction buffer solution at 25° C. for 3 hours. The reaction mixture was rapidly filtered through a glass filter (GF/B, Whatman, U.S.A.) using a cell harvester (Type 290PHD, Cambridge Technology Inc.) to terminate the reaction, and washed 3 times with 250 μl of 50 mM Tris-HCl buffer (pH 7.4) supplemented with 0.02% bovine serum albumin. The radioactivity left on the filter was measured with a gamma-ray counter. Results are shown in Table 1 as the binding inhibiting activity (IC50, unit: μM) on the NK2 receptor.
                                  TABLE 1                                 
__________________________________________________________________________
                                           Binding Activity               
                                                      Binding Inhibiting  
                                           on ET Receptor                 
                                                      Activity            
Example                                    (R. act.)  on NK2 Receptor     
No.  Compound                              ET.sub.A                       
                                              ET.sub.8 *1                 
                                                  ET.sub.8 *2             
                                                      (IC.sub.50,         
__________________________________________________________________________
                                                      μM)              
 1   Cyclo[--D--Asp--Ala--Asp--D--Leu--Leu--D--Trp--]                     
                                           9.7                            
                                              13  2.0                     
 2   Cyclo[--D--Asp--Ala--D--Asp--D--Leu--Leu--D--Trp--]                  
                                           3.7    3.1                     
 3   Cyclo[--D--Asp--Ala--Glu--D--Leu--Leu--D--Trp--]                     
                                           7.9    23                      
 4   Cyclo[--D--Asp--Ala--D--Glu--D--Leu--Leu--D--Trp--]                  
                                           2.3    1.4                     
 5   Cyclo[--D--Asp--Gly--Ala--D--Leu--Leu--D--Trp--]                     
                                           1.3    --                      
 6   Cyclo[--D--Asp--Asp--Ala--D--Leu--Leu--D--Trp--]                     
                                           6.0    7.1                     
 7   Cyclo[--D--Asp--Glu--Ala--D--Leu--Leu--D--Trp--]                     
                                           6.5    7.1                     
 8   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp--]                     
                                           76 100 100 6.4                 
 9   Cyclo[--D--Asp--Pro--Asp--D--Leu--Leu--D--Trp--]                     
                                           56 140 67                      
10   Cyclo[--D--Asp--Asn(CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--]        
                                           43 26  24                      
11   Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--
     ]                                     93 42  44                      
12   Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Leu--Leu--D--Tr
     p--]                                  220                            
                                              230 150                     
13   Cyclo[--D--Asp--Hyp(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           83 85  140                     
14   Cyclo[--D--Asp--Hyp--Asp--D--Leu--Leu--D--Trp--]                     
                                           70 160 120                     
15   Cyclo[--D--Asp--D--Ala--Asp--D--Leu--Leu--D--Trp--]                  
                                           5.7    7.7                     
16   Cyclo[--D--Asp--Asp--Asp--D--Leu--Leu--D--Trp--]                     
                                           10 14  34                      
17   Cyclo[--D--Asp--Val--Asp--D--Leu--Leu--D--Trp--]                     
                                           3.7    22                      
18   Cyclo[--D--Asp--Leu--Asp--D--Leu--Leu--D--Trp--]                     
                                           13     2.2                     
19   Cyclo[--D--Asp--Phe--Asp--D--Leu--Leu--D--Trp--]                     
                                           8.3    7.1                     
20   Cyclo[--D--Asp--Ser(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           14     13                      
21   Cyclo[--D--Asp--Thr(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           4.3    5.0                     
22   Cyclo[--D--Asp--Trp(For)--Asp--D--Leu--Leu--D--Trp--]                
                                           8.3                            
                                              6.7 15                      
23   Cyclo[--D--Asp--Nal(1)--Asp--D--Leu--Leu--D--Trp--]                  
                                           8.3                            
                                              11  7.7 2.1                 
24   Cyclo[--D--Asp--D--Pro--Asp--D--Leu--Leu--D--Trp--]                  
                                           1.7    --                      
25   Cyclo[--D--Asp--Azc--Asp--D--Leu--Leu--D--Trp--]                     
                                           30 25  57                      
26   Cyclo[--D--Asp--Pip--Asp--D--Leu--Leu--D--Trp--]                     
                                           25 38  73                      
27   Cyclo[--D--Asp--D--Asp--Ala--D--Leu--Leu--D--Trp--]                  
                                           5.7    4.8                     
28   Cyclo[--D--Asp--D--Glu--Ala--D--Leu--Leu--D--Trp--]                  
                                           5.7    5.3                     
29   Cyclo[--D--Asp--Asp--D--Ala--D--Leu--Leu--D--Trp--]                  
                                           2.6    2.4                     
30   Cyclo[--D--Asp--Asp--Pro--D--Leu--Leu--D--Trp--]                     
                                           4.4    9.1                     
31   Cyclo[--D--Asp--Asp--D--Pro--D--Leu--Leu--D--Trp--]                  
                                           2.6    1.0                     
32   Cyclo[--D--Asp--Asp--Leu--D--Leu--Leu--D--Trp--]                     
                                           4.0    7.7 2.6                 
33   Cyclo[--D--Asp--Asp--Trp--D--Leu--Leu--D--Trp--]                     
                                           2.9    5.6 0.35                
34   Cyclo[--D--Asp--Trp--Glu--D--Leu--Leu--D--Trp--]                     
                                           20 77  44  7.4                 
35   Cyclo[--D--Asp--Trp--Leu--D--Leu--Leu--D--Trp--]                     
                                           9.1                            
                                              52  24  0.052               
36   Cyclo[--D--Asp--Trp--Pro--D--Leu--Leu--D--Trp--]                     
                                           17 40  42  1.1                 
37   Cyclo[--D--Asp--Trp--Ser--D--Leu--Leu--D--Trp--]                     
                                           24 22  18  0.28                
38   Cyclo[--D--Asp--Trp--Ser(Bzl)--D--Leu--Leu--D--Trp--]                
                                           13 66  170 0.070               
39   Cyclo[--D--Asp--Ala--Asp--D--tLeu--Leu--D--Trp--]                    
                                           6.8                            
                                              59  53                      
40   Cyclo[--D--Glu--Ala--Gly--D--Leu--Leu--D--Trp--]                     
                                           1.4                            
41   Cyclo[--D--Glu--Ala--Asp--D--Leu--Leu--D--Trp--]                     
                                           2.1    26                      
42   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(For)--]                
                                           150                            
                                              100 150                     
43   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(Ac)--]                 
                                           8.2                            
                                              120 250                     
44   Cyclo[--D--Asp--Trp--Asp--Acpe--Leu--D--Trp--]                       
                                           34     11                      
45   Cyclo[--D--Asp--Trp--Asp--D--Phg--Leu--D--Trp--]                     
                                           87 74  180                     
46   Cyclo[--D--Asp--Sar--Asp--D--Leu--Leu--D--Trp--]                     
                                           8.1    75                      
47   Cyclo[--D--Asp--N-MeLeu--Asp--D--Leu--Leu--D--Trp--]                 
                                           6.8    17                      
48   Cyclo[--D--Asp--N-MePhe--Asp--D--Leu--Leu--D--Trp--]                 
                                           2.7    13                      
49   Cyclo[--D--Asp--Trp--Asp--D--Thg(3)--Leu--D--Trp--]                  
                                           270                            
                                              74  75                      
50   Cyclo[--D--Asp--Trp--Asp--D--Thi--Leu--D--Trp--]                     
                                           4  350 57                      
51   Cyclo[--D--Asp--Trp--Asp--D--aIle--Leu--D--Trp--]                    
                                           100                            
                                              210 290                     
52   Cyclo[--D--Asp--Trp--Asp--D--Val--Leu--D--Trp--]                     
                                           75 240 100                     
53   Cyclo[--D--Asp--Trp--Asp--D--tLeu--Leu--D--Trp--]                    
                                           64     460                     
54   Cyclo[--D--Asp--Trp--Asp--D--γMeLeu--Leu--D--Trp--]            
                                           99     1000                    
55   Cyclo[--D--Asp--Trp--Asp--D--Thg(2)--Leu--D--Trp--]                  
                                           340    120                     
56   Cyclo[--D--Asp--Trp--Asp--Acbu--Leu--D--Trp--]                       
                                           51     4.3                     
57   Cyclo[--D--Asp--Ala--Asp--D--Leu--Phe--D--Trp--]                     
                                                  2.0                     
58   Cyclo[--D--Asp--Ala--Asp--D--Leu--Trp--D--Trp--]                     
                                           0.7                            
                                              6.7 22                      
59   Cyclo[--D--Glu--Gly--Ala--D--Leu--Leu--D--Trp--]                     
60   Cyclo[--D--Asp--Trp--Asp--D--Phe--Leu--D--Trp--]                     
                                           1  210 44                      
61   Cyclo[--D--Asp--Trp--Asp--Achx--Leu--D--Trp--]                       
                                           39     52                      
62   Cyclo[--D--Asp--Gln(CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--]        
                                           170    120                     
63   Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--
     ]                                     130    340                     
64   Cyclo[--D--Asp--Gln(CH.sub.2 CH.sub.2 --Ind)--Asp--D--Leu--Leu--D--Tr
     p--]                                  120    270                     
65   Cyclo[--D--Asp--Arg(Tos)--Asp--D--Leu--Leu--D--Trp--]                
                                           20     63                      
66   Cyclo[--D--Asp--Lys(Mtr)--Asp--D--Leu--Leu--D--Trp--]                
                                           51     120                     
67   Cyclo[--D--Asp--N-MeTrp--Asp--D--Leu--Leu--D--Trp--]                 
                                           9.1    30                      
68   Cyclo[--D--Asp--Asn(Me.CH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Tr
     p--]                                  24     52                      
69   Cyclo[--D--Asp--Asn(CH.sub.2 CHMePh)--Asp--D--Leu--Leu--D--Trp--]    
                                           140    60                      
70   Cyclo[--D--Asp--Asp(R1)--Asp--D--Leu--Leu--D--Trp--]                 
                                           360                            
                                              1500                        
                                                  2600                    
71   Cyclo[--D--Asp--Asp(R2)--Asp--D--Leu--Leu--D--Trp--]                 
                                           160    1000                    
72   Cyclo[--D--Asp--Asp(R3)--Asp--D--Leu--Leu--D--Trp--]                 
                                           45     100                     
73   Cyclo[--D--Asp--Asp(R4)--Asp--D--Leu--Leu--D--Trp--]                 
                                           80     40                      
74   Cyclo[--D--Asp--Asp(R5)--Asp--D--Leu--Leu--D--Trp--]                 
                                           37     31                      
75   Cyclo[--D--Asp--Asp(R6)--Asp--D--Leu--Leu--D--Trp--]                 
                                           9      33                      
76   Cyclo[--D--Asp--Glu(R3)--Asp--D--Leu--Leu--D--Trp--]                 
                                           17     57  10                  
77   Cyclo[--D--Asp--Glu(R4)--Asp--D--Leu--Leu--D--Trp--]                 
                                           66     100                     
78   Cyclo[--D--Asp--Glu(R5)--Asp--D--Leu--Leu--D--Trp--]                 
                                           120    130                     
79   Cyclo[--D--Asp--Orn(COPh)--Asp--D--Leu--Leu--D--Trp--]               
                                           26     71                      
80   Cyclo[--D--Asp--Orn(COCH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp--]      
                                           260    380                     
81   Cyclo[--D--Asp--Orn(COCH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D--Trp
     --]                                   68     160                     
82   Cyclo[--D--Asp--Orn(COCH.sub.2 --Ind)--Asp--D--Leu--Leu--D--Trp--]   
                                           240    500                     
83   Cyclo[--D--Asp--His--Asp--D--Leu--Trp--D--Trp--]                     
                                           15     43                      
84   Cyclo[--D--Asp--His(Bom)--Asp--D--Leu--Leu--D--Trp--]                
                                           20     80                      
85   Cyclo[--D--Asp--His(Bzl)--Asp--D--Leu--Leu--D--Trp--]                
                                           19     43                      
86   Cyclo[--D--Asp--D,L-Tic--Asp--D--Leu--Leu--D--Trp--]                 
                                           38     240                     
87   Cyclo[--D--Asp--Tpr--Asp--D--Leu--Leu--D--Trp--]                     
                                           93     380                     
88   Cyclo[--D--Asp--Hyp(Bzl)--Asp--D--Thg(2)--Leu--D--Trp--]             
                                           650                            
                                              200 210                     
89   Cyclo[--D--Asp--Glu(Bzl)--Asp--D--Thg(2)--Leu--D--Trp--]             
                                           750                            
                                              45  71                      
90   Cyclo[--D--Asp--Asn(CH.sub.2 CH.sub.2 Ind)--Asp--D--Thg(2)--Leu--D--T
     rp--]                                 810                            
                                              590 280                     
91   Cyclo[--D--Asp--Asp(Trp--NHET)--Asp--D--Leu--Leu--D--Trp--]          
                                           130    200                     
92   Cyclo[--D--Asp--Asp(Trp--NHBzl)--Asp--D--Leu--Leu--D--Trp--]         
                                           95     260 4.0                 
93   Cyclo[--D--Asp--Asp(D--Trp--NHBzl)--Asp--D--Leu--Leu--D--Trp--]      
                                           110    270                     
94   Cyclo[--D--Asp--Asp(Trp--NHCH.sub.2 CH.sub.2 Ph)--Asp--D--Leu--Leu--D
     --Trp--]                              120    140 5.8                 
95   Cyclo[--D--Asp--Trp--Asp--D--Leu--Leu--D--Trp(Me)--]                 
                                           110    330                     
96   Cyclo[--D--Asp--Asp(R1)--Asp--D--Thg(2)--Leu--D--Trp--]              
                                           980                            
                                              1800                        
__________________________________________________________________________

__________________________________________________________________________
SEQUENCE LISTING                                                          
(1) GENERAL INFORMATION:                                                  
(iii) NUMBER OF SEQUENCES: 3                                              
(2) INFORMATION FOR SEQ ID NO:1:                                          
(i) SEQUENCE CHARACTERISTICS:                                             
(A) LENGTH: 21 amino acids                                                
(B) TYPE: amino acid                                                      
(D) TOPOLOGY: linear                                                      
(ii) MOLECULE TYPE: protein                                               
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                   
CysSerCysSerSerLeuMetAspLysGluCysValTyrPheCysHis                          
151015                                                                    
LeuAspIleIleTrp                                                           
20                                                                        
(2) INFORMATION FOR SEQ ID NO:2:                                          
(i) SEQUENCE CHARACTERISTICS:                                             
(A) LENGTH: 21 amino acids                                                
(B) TYPE: amino acid                                                      
(D) TOPOLOGY: linear                                                      
(ii) MOLECULE TYPE: protein                                               
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                   
CysSerCysSerSerTrpLeuAspLysGluCysValTyrPheCysHis                          
151015                                                                    
LeuAspIleIleTrp                                                           
20                                                                        
(2) INFORMATION FOR SEQ ID NO:3:                                          
(i) SEQUENCE CHARACTERISTICS:                                             
(A) LENGTH: 21 amino acids                                                
(B) TYPE: amino acid                                                      
(D) TOPOLOGY: linear                                                      
(ii) MOLECULE TYPE: protein                                               
(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                   
CysThrCysPheThrTyrLysAspLysGluCysValTyrTyrCysHis                          
151015                                                                    
LeuAspIleIleTrp                                                           
20                                                                        
__________________________________________________________________________

Claims (1)

What is claimed is:
1. A cyclic peptide having endothelin receptor antagonistic activity represented by formula [I] or a pharmaceutically acceptable salt thereof: ##STR4## wherein A is D-aspartic acid, X is aspartic acid β-4-phenylpiperazineamide, Y is aspartic acid, B is D-2-thienylglycine, C is leucine and D is D-tryptophan.
US08/231,449 1991-08-13 1994-04-20 Cyclic peptides and use thereof Expired - Fee Related US5616684A (en)

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JP3-203032 1992-04-30
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JP3-303635 1992-04-30
JP4-111792 1992-04-30
JP11179292 1992-04-30
US92720592A 1992-08-07 1992-08-07
US08/231,449 US5616684A (en) 1991-08-13 1994-04-20 Cyclic peptides and use thereof

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US6251861B1 (en) * 1996-06-27 2001-06-26 Takeda Chemical Industries, Ltd. Treatment of cerebral infarction using cyclic hexapeptides
WO2005085277A1 (en) * 2004-02-06 2005-09-15 Concepcion Gisela P Cyclic hexapeptides, process and use thereof
US20100022568A1 (en) * 2006-04-13 2010-01-28 Actelion Pharmaceeuticals Ltd. Endothelin receptor antagonists for early stage idiopathic pulmonary fibrosis
US9486273B2 (en) 2011-01-21 2016-11-08 Kardium Inc. High-density electrode-based medical device system
WO2024114782A1 (en) * 2022-12-01 2024-06-06 National Institute Of Biological Sciences, Beijing Small-molecule modulators of spike protein

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US6087324A (en) 1993-06-24 2000-07-11 Takeda Chemical Industries, Ltd. Sustained-release preparation
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US5521156A (en) * 1994-02-03 1996-05-28 Merrell Pharmaceuticals Inc. Cyclic neurokinin A antagonists
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US5559135A (en) * 1994-09-14 1996-09-24 Merck & Co., Inc. Endothelin antagonists bearing pyridyl amides
US5538991A (en) * 1994-09-14 1996-07-23 Merck & Co., Inc. Endothelin antagonists bearing 5-membered heterocyclic amides
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US7838102B2 (en) * 2004-10-28 2010-11-23 E. I. Du Pont De Nemours And Company Filled polyvinyl butyral sheeting for decorative laminated glass and a process for making same
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5811218A (en) * 1993-07-28 1998-09-22 Hitachi Chemical Company, Ltd. Photoinitiator compositions including amino acids, coumarin and titanocene and photosensitive materials using the same
US6251861B1 (en) * 1996-06-27 2001-06-26 Takeda Chemical Industries, Ltd. Treatment of cerebral infarction using cyclic hexapeptides
WO2005085277A1 (en) * 2004-02-06 2005-09-15 Concepcion Gisela P Cyclic hexapeptides, process and use thereof
US20100022568A1 (en) * 2006-04-13 2010-01-28 Actelion Pharmaceeuticals Ltd. Endothelin receptor antagonists for early stage idiopathic pulmonary fibrosis
US9486273B2 (en) 2011-01-21 2016-11-08 Kardium Inc. High-density electrode-based medical device system
WO2024114782A1 (en) * 2022-12-01 2024-06-06 National Institute Of Biological Sciences, Beijing Small-molecule modulators of spike protein

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JP2726647B2 (en) 1998-03-11
FI923619A0 (en) 1992-08-12

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